Merge WebKit at r67178 : Initial merge by git.

Change-Id: I57e01163b6866cb029cdadf405a0394a3918bc18

7 files changed, 429 insertions, 88 deletions

diff --git a/WebCore/platform/graphics/skia/FontCustomPlatformData.cpp b/WebCore/platform/graphics/skia/FontCustomPlatformData.cpp
new file mode 100644
index 0000000..b6d6e65
--- /dev/null
+++ b/WebCore/platform/graphics/skia/FontCustomPlatformData.cpp
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2007 Apple Computer, Inc.
+ * Copyright (c) 2007, 2008, 2009, Google Inc. All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "FontCustomPlatformData.h"
+
+#if OS(WINDOWS)
+#include "Base64.h"
+#include "ChromiumBridge.h"
+#include "OpenTypeUtilities.h"
+#elif OS(LINUX)
+#include "SkStream.h"
+#endif
+
+#include "FontPlatformData.h"
+#include "NotImplemented.h"
+#include "OpenTypeSanitizer.h"
+#include "SharedBuffer.h"
+
+#if OS(WINDOWS)
+#include <objbase.h>
+#elif OS(LINUX)
+#include <cstring>
+#endif
+
+namespace WebCore {
+
+FontCustomPlatformData::~FontCustomPlatformData()
+{
+#if OS(WINDOWS)
+    if (m_fontReference)
+        RemoveFontMemResourceEx(m_fontReference);
+#elif OS(LINUX)
+    if (m_fontReference)
+        m_fontReference->unref();
+#endif
+}
+
+FontPlatformData FontCustomPlatformData::fontPlatformData(int size, bool bold, bool italic, FontRenderingMode mode)
+{
+#if OS(WINDOWS)
+    ASSERT(m_fontReference);
+
+    LOGFONT logFont;
+    // m_name comes from createUniqueFontName, which, in turn, gets
+    // it from base64-encoded uuid (128-bit). So, m_name
+    // can never be longer than LF_FACESIZE (32).
+    if (m_name.length() + 1 >= LF_FACESIZE) {
+        ASSERT_NOT_REACHED();
+        return FontPlatformData();
+    }
+    memcpy(logFont.lfFaceName, m_name.charactersWithNullTermination(),
+           sizeof(logFont.lfFaceName[0]) * (1 + m_name.length()));
+
+    // FIXME: almost identical to FillLogFont in FontCacheWin.cpp.
+    // Need to refactor. 
+    logFont.lfHeight = -size;
+    logFont.lfWidth = 0;
+    logFont.lfEscapement = 0;
+    logFont.lfOrientation = 0;
+    logFont.lfUnderline = false;
+    logFont.lfStrikeOut = false;
+    logFont.lfCharSet = DEFAULT_CHARSET;
+    logFont.lfOutPrecision = OUT_TT_ONLY_PRECIS;
+    logFont.lfQuality = ChromiumBridge::layoutTestMode() ?
+                        NONANTIALIASED_QUALITY :
+                        DEFAULT_QUALITY; // Honor user's desktop settings.
+    logFont.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
+    logFont.lfItalic = italic;
+    logFont.lfWeight = bold ? 700 : 400;
+
+    HFONT hfont = CreateFontIndirect(&logFont);
+    return FontPlatformData(hfont, size);
+#elif OS(LINUX)
+    ASSERT(m_fontReference);
+    return FontPlatformData(m_fontReference, "", size, bold && !m_fontReference->isBold(), italic && !m_fontReference->isItalic());
+#else
+    notImplemented();
+    return FontPlatformData();
+#endif
+}
+
+#if OS(WINDOWS)
+// Creates a unique and unpredictable font name, in order to avoid collisions and to
+// not allow access from CSS.
+static String createUniqueFontName()
+{
+    Vector<char> fontUuid(sizeof(GUID));
+    CoCreateGuid(reinterpret_cast<GUID*>(fontUuid.data()));
+
+    Vector<char> fontNameVector;
+    base64Encode(fontUuid, fontNameVector);
+    ASSERT(fontNameVector.size() < LF_FACESIZE);
+    return String(fontNameVector.data(), fontNameVector.size());
+}
+#endif
+
+#if OS(LINUX)
+class RemoteFontStream : public SkStream {
+public:
+    explicit RemoteFontStream(PassRefPtr<SharedBuffer> buffer)
+        : m_buffer(buffer)
+        , m_offset(0)
+    {
+    }
+
+    virtual ~RemoteFontStream()
+    {
+    }
+
+    virtual bool rewind()
+    {
+        m_offset = 0;
+        return true;
+    }
+
+    virtual size_t read(void* buffer, size_t size)
+    {
+        if (!buffer && !size) {
+            // This is request for the length of the stream.
+            return m_buffer->size();
+        }
+        if (!buffer) {
+            // This is a request to skip bytes. This operation is not supported.
+            return 0;
+        }
+        // This is a request to read bytes.
+        if (!m_buffer->data() || !m_buffer->size())
+            return 0;
+        size_t left = m_buffer->size() - m_offset;
+        size_t toRead = (left > size) ? size : left;
+        std::memcpy(buffer, m_buffer->data() + m_offset, toRead);
+        m_offset += toRead;
+        return toRead;
+    }
+
+private:
+    RefPtr<SharedBuffer> m_buffer;
+    size_t m_offset;
+};
+#endif
+
+FontCustomPlatformData* createFontCustomPlatformData(SharedBuffer* buffer)
+{
+    ASSERT_ARG(buffer, buffer);
+
+#if ENABLE(OPENTYPE_SANITIZER)
+    OpenTypeSanitizer sanitizer(buffer);
+    RefPtr<SharedBuffer> transcodeBuffer = sanitizer.sanitize();
+    if (!transcodeBuffer)
+        return 0; // validation failed.
+    buffer = transcodeBuffer.get();
+#endif
+
+#if OS(WINDOWS)
+    // Introduce the font to GDI. AddFontMemResourceEx should be used with care, because it will pollute the process's
+    // font namespace (Windows has no API for creating an HFONT from data without exposing the font to the
+    // entire process first).
+    String fontName = createUniqueFontName();
+    HANDLE fontReference = renameAndActivateFont(buffer, fontName);
+    if (!fontReference)
+        return 0;
+    return new FontCustomPlatformData(fontReference, fontName);
+#elif OS(LINUX)
+    RemoteFontStream* stream = new RemoteFontStream(buffer);
+    SkTypeface* typeface = SkTypeface::CreateFromStream(stream);
+    if (!typeface)
+        return 0;
+    return new FontCustomPlatformData(typeface);
+#else
+    notImplemented();
+    return 0;
+#endif
+}
+
+bool FontCustomPlatformData::supportsFormat(const String& format)
+{
+    return equalIgnoringCase(format, "truetype") || equalIgnoringCase(format, "opentype")
+#if ENABLE(OPENTYPE_SANITIZER)
+        || equalIgnoringCase(format, "woff")
+#endif
+    ;
+}
+
+}
diff --git a/WebCore/platform/graphics/skia/FontCustomPlatformData.h b/WebCore/platform/graphics/skia/FontCustomPlatformData.h
new file mode 100644
index 0000000..d451c9c
--- /dev/null
+++ b/WebCore/platform/graphics/skia/FontCustomPlatformData.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2007 Apple Computer, Inc.
+ * Copyright (c) 2007, 2008, 2009, Google Inc. All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef FontCustomPlatformData_h
+#define FontCustomPlatformData_h
+
+#include "FontRenderingMode.h"
+#include <wtf/Forward.h>
+#include <wtf/Noncopyable.h>
+
+#if OS(WINDOWS)
+#include "PlatformString.h"
+#include <windows.h>
+#elif OS(LINUX)
+#include "SkTypeface.h"
+#endif
+
+namespace WebCore {
+
+class FontPlatformData;
+class SharedBuffer;
+
+struct FontCustomPlatformData : Noncopyable {
+#if OS(WINDOWS)
+    FontCustomPlatformData(HANDLE fontReference, const String& name)
+        : m_fontReference(fontReference)
+        , m_name(name)
+    {}
+#elif OS(LINUX)
+    explicit FontCustomPlatformData(SkTypeface* typeface)
+        : m_fontReference(typeface)
+    {}
+#endif
+
+    ~FontCustomPlatformData();
+
+    FontPlatformData fontPlatformData(int size, bool bold, bool italic,
+                                      FontRenderingMode = NormalRenderingMode);
+
+    static bool supportsFormat(const String&);
+
+#if OS(WINDOWS)
+    HANDLE m_fontReference;
+    String m_name;
+#elif OS(LINUX)
+    SkTypeface* m_fontReference;
+#endif
+};
+
+FontCustomPlatformData* createFontCustomPlatformData(SharedBuffer*);
+}
+
+#endif // FontCustomPlatformData_h
diff --git a/WebCore/platform/graphics/skia/GraphicsContextSkia.cpp b/WebCore/platform/graphics/skia/GraphicsContextSkia.cpp
index 1c80d49..d618c19 100644
--- a/WebCore/platform/graphics/skia/GraphicsContextSkia.cpp
+++ b/WebCore/platform/graphics/skia/GraphicsContextSkia.cpp
@@ -1,10 +1,10 @@
 /*
  * Copyright (c) 2006, Google Inc. All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
- * 
+ *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ -14,7 +14,7 @@
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
@@ -65,7 +65,7 @@ namespace {
 inline int fastMod(int value, int max)
 {
     int sign = SkExtractSign(value);
-    
+
     value = SkApplySign(value, sign);
     if (value >= max)
         value %= max;
@@ -391,7 +391,7 @@ void GraphicsContext::canvasClip(const Path& path)
     if (!isPathSkiaSafe(getCTM(), p))
         return;
 
-    platformContext()->canvas()->clipPath(p);
+    platformContext()->canvasClipPath(p);
 }
 
 void GraphicsContext::clipOut(const IntRect& rect)
@@ -499,7 +499,7 @@ void GraphicsContext::clipConvexPolygon(size_t numPoints, const FloatPoint* poin
 
     if (numPoints <= 1)
         return;
-    
+
     // FIXME: IMPLEMENT!!
 }
 
@@ -767,7 +767,7 @@ void GraphicsContext::fillRect(const FloatRect& rect)
         ClipRectToCanvas(*platformContext()->canvas(), r, &r);
     }
 
-    if (platformContext()->useGPU() && !m_common->state.fillPattern && !m_common->state.fillGradient && !platformContext()->getDrawLooper()) {
+    if (platformContext()->useGPU() && platformContext()->canAccelerate()) {
         platformContext()->prepareForHardwareDraw();
         platformContext()->gpuCanvas()->fillRect(rect);
         return;
@@ -789,7 +789,7 @@ void GraphicsContext::fillRect(const FloatRect& rect, const Color& color, ColorS
     if (paintingDisabled())
         return;
 
-    if (platformContext()->useGPU() && !m_common->state.fillPattern && !m_common->state.fillGradient) {
+    if (platformContext()->useGPU() && platformContext()->canAccelerate()) {
         platformContext()->prepareForHardwareDraw();
         platformContext()->gpuCanvas()->fillRect(rect, color, colorSpace);
         return;
@@ -1240,14 +1240,19 @@ void GraphicsContext::translate(float w, float h)
                                            WebCoreFloatToSkScalar(h));
 }
 
-void GraphicsContext::setGraphicsContext3D(GraphicsContext3D* context3D, const IntSize& size)
+void GraphicsContext::syncSoftwareCanvas()
 {
-    platformContext()->setGraphicsContext3D(context3D, size);
+    platformContext()->syncSoftwareCanvas();
 }
 
-void GraphicsContext::syncSoftwareCanvas()
+void GraphicsContext::setSharedGraphicsContext3D(SharedGraphicsContext3D* context, DrawingBuffer* framebuffer, const IntSize& size)
 {
-    platformContext()->syncSoftwareCanvas();
+    platformContext()->setSharedGraphicsContext3D(context, framebuffer, size);
+}
+
+void GraphicsContext::markDirtyRect(const IntRect& rect)
+{
+    platformContext()->markDirtyRect(rect);
 }
 
 }  // namespace WebCore
diff --git a/WebCore/platform/graphics/skia/ImageBufferSkia.cpp b/WebCore/platform/graphics/skia/ImageBufferSkia.cpp
index 9403406..2be7dc5 100644
--- a/WebCore/platform/graphics/skia/ImageBufferSkia.cpp
+++ b/WebCore/platform/graphics/skia/ImageBufferSkia.cpp
@@ -36,10 +36,12 @@
 #include "Base64.h"
 #include "BitmapImage.h"
 #include "BitmapImageSingleFrameSkia.h"
+#include "DrawingBuffer.h"
+#include "GLES2Canvas.h"
 #include "GraphicsContext.h"
 #include "ImageData.h"
-#include "PlatformContextSkia.h"
 #include "PNGImageEncoder.h"
+#include "PlatformContextSkia.h"
 #include "SkColorPriv.h"
 #include "SkiaUtils.h"
 
@@ -67,9 +69,7 @@ ImageBuffer::ImageBuffer(const IntSize& size, ImageColorSpace imageColorSpace, b
 
     m_data.m_platformContext.setCanvas(&m_data.m_canvas);
     m_context.set(new GraphicsContext(&m_data.m_platformContext));
-#if OS(WINDOWS)
     m_context->platformContext()->setDrawingToImageBuffer(true);
-#endif
 
     // Make the background transparent. It would be nice if this wasn't
     // required, but the canvas is currently filled with the magic transparency
@@ -100,14 +100,26 @@ PassRefPtr<Image> ImageBuffer::copyImage() const
 
 void ImageBuffer::clip(GraphicsContext* context, const FloatRect& rect) const
 {
-#if OS(LINUX) || OS(WINDOWS)
     context->platformContext()->beginLayerClippedToImage(rect, this);
-#endif
 }
 
 void ImageBuffer::draw(GraphicsContext* context, ColorSpace styleColorSpace, const FloatRect& destRect, const FloatRect& srcRect,
                        CompositeOperator op, bool useLowQualityScale)
 {
+    if (m_data.m_platformContext.useGPU() && context->platformContext()->useGPU()) {
+        if (context->platformContext()->canAccelerate()) {
+            DrawingBuffer* sourceDrawingBuffer = m_data.m_platformContext.gpuCanvas()->drawingBuffer();
+            unsigned sourceTexture = sourceDrawingBuffer->getRenderingResultsAsTexture();
+            FloatRect destRectFlipped(destRect);
+            destRectFlipped.setY(destRect.y() + destRect.height());
+            destRectFlipped.setHeight(-destRect.height());
+            context->platformContext()->prepareForHardwareDraw();
+            context->platformContext()->gpuCanvas()->drawTexturedRect(sourceTexture, m_size, srcRect, destRectFlipped, styleColorSpace, op);
+            return;
+        }
+        m_data.m_platformContext.syncSoftwareCanvas();
+    }
+
     RefPtr<Image> image = BitmapImageSingleFrameSkia::create(*m_data.m_platformContext.bitmap(), context == m_context);
     context->drawImage(image.get(), styleColorSpace, destRect, srcRect, op, useLowQualityScale);
 }
diff --git a/WebCore/platform/graphics/skia/ImageSkia.cpp b/WebCore/platform/graphics/skia/ImageSkia.cpp
index aed289f..9625b34 100644
--- a/WebCore/platform/graphics/skia/ImageSkia.cpp
+++ b/WebCore/platform/graphics/skia/ImageSkia.cpp
@@ -47,6 +47,7 @@
 #include "SkRect.h"
 #include "SkShader.h"
 #include "SkiaUtils.h"
+#include "Texture.h"
 
 #include "skia/ext/image_operations.h"
 #include "skia/ext/platform_canvas.h"
@@ -468,7 +469,7 @@ void BitmapImage::draw(GraphicsContext* ctxt, const FloatRect& dstRect,
     if (normSrcRect.isEmpty() || normDstRect.isEmpty())
         return;  // Nothing to draw.
 
-    if (ctxt->platformContext()->useGPU()) {
+    if (ctxt->platformContext()->useGPU() && ctxt->platformContext()->canAccelerate()) {
         drawBitmapGLES2(ctxt, bm, normSrcRect, normDstRect, colorSpace, compositeOp);
         return;
     }
@@ -496,7 +497,7 @@ void BitmapImageSingleFrameSkia::draw(GraphicsContext* ctxt,
     if (normSrcRect.isEmpty() || normDstRect.isEmpty())
         return;  // Nothing to draw.
 
-    if (ctxt->platformContext()->useGPU()) {
+    if (ctxt->platformContext()->useGPU() && ctxt->platformContext()->canAccelerate()) {
         drawBitmapGLES2(ctxt, &m_nativeImage, srcRect, dstRect, styleColorSpace, compositeOp);
         return;
     }
diff --git a/WebCore/platform/graphics/skia/PlatformContextSkia.cpp b/WebCore/platform/graphics/skia/PlatformContextSkia.cpp
index 3b1d015..88fbcdd 100644..100755
--- a/WebCore/platform/graphics/skia/PlatformContextSkia.cpp
+++ b/WebCore/platform/graphics/skia/PlatformContextSkia.cpp
@@ -1,10 +1,10 @@
 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
- * 
+ *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ -14,7 +14,7 @@
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
@@ -33,12 +33,13 @@
 #include "PlatformContextSkia.h"
 
 #include "AffineTransform.h"
-#include "CanvasLayerChromium.h"
+#include "DrawingBuffer.h"
 #include "GLES2Canvas.h"
 #include "GraphicsContext.h"
 #include "GraphicsContext3D.h"
 #include "ImageBuffer.h"
 #include "NativeImageSkia.h"
+#include "SharedGraphicsContext3D.h"
 #include "SkiaUtils.h"
 #include "Texture.h"
 #include "TilingData.h"
@@ -96,18 +97,19 @@ struct PlatformContextSkia::State {
     // color to produce a new output color.
     SkColor applyAlpha(SkColor) const;
 
-#if OS(LINUX) || OS(WINDOWS)
     // If non-empty, the current State is clipped to this image.
     SkBitmap m_imageBufferClip;
     // If m_imageBufferClip is non-empty, this is the region the image is clipped to.
     FloatRect m_clip;
-#endif
 
     // This is a list of clipping paths which are currently active, in the
     // order in which they were pushed.
     WTF::Vector<SkPath> m_antiAliasClipPaths;
     InterpolationQuality m_interpolationQuality;
 
+    // If we currently have a canvas (non-antialiased path) clip applied.
+    bool m_canvasClipApplied;
+
     PlatformContextSkia::State cloneInheritedProperties();
 private:
     // Not supported.
@@ -133,6 +135,7 @@ PlatformContextSkia::State::State()
     , m_dash(0)
     , m_textDrawingMode(cTextFill)
     , m_interpolationQuality(InterpolationHigh)
+    , m_canvasClipApplied(false)
 {
 }
 
@@ -153,12 +156,11 @@ PlatformContextSkia::State::State(const State& other)
     , m_lineJoin(other.m_lineJoin)
     , m_dash(other.m_dash)
     , m_textDrawingMode(other.m_textDrawingMode)
-#if OS(LINUX) || OS(WINDOWS)
     , m_imageBufferClip(other.m_imageBufferClip)
     , m_clip(other.m_clip)
-#endif
     , m_antiAliasClipPaths(other.m_antiAliasClipPaths)
     , m_interpolationQuality(other.m_interpolationQuality)
+    , m_canvasClipApplied(other.m_canvasClipApplied)
 {
     // Up the ref count of these. saveRef does nothing if 'this' is NULL.
     m_looper->safeRef();
@@ -181,7 +183,7 @@ PlatformContextSkia::State PlatformContextSkia::State::cloneInheritedProperties(
     PlatformContextSkia::State state(*this);
 
     // Everything is inherited except for the clip paths.
-    state.m_antiAliasClipPaths.clear();  
+    state.m_antiAliasClipPaths.clear();
 
     return state;
 }
@@ -203,9 +205,7 @@ SkColor PlatformContextSkia::State::applyAlpha(SkColor c) const
 // Danger: canvas can be NULL.
 PlatformContextSkia::PlatformContextSkia(skia::PlatformCanvas* canvas)
     : m_canvas(canvas)
-#if OS(WINDOWS)
     , m_drawingToImageBuffer(false)
-#endif
     , m_useGPU(false)
     , m_gpuCanvas(0)
     , m_backingStoreState(None)
@@ -216,12 +216,8 @@ PlatformContextSkia::PlatformContextSkia(skia::PlatformCanvas* canvas)
 
 PlatformContextSkia::~PlatformContextSkia()
 {
-#if USE(ACCELERATED_COMPOSITING)
-    if (m_gpuCanvas) {
-        CanvasLayerChromium* layer = static_cast<CanvasLayerChromium*>(m_gpuCanvas->context()->platformLayer());
-        layer->setPrepareTextureCallback(0);
-    }
-#endif
+    if (m_gpuCanvas)
+        m_gpuCanvas->drawingBuffer()->setWillPublishCallback(0);
 }
 
 void PlatformContextSkia::setCanvas(skia::PlatformCanvas* canvas)
@@ -229,7 +225,6 @@ void PlatformContextSkia::setCanvas(skia::PlatformCanvas* canvas)
     m_canvas = canvas;
 }
 
-#if OS(WINDOWS)
 void PlatformContextSkia::setDrawingToImageBuffer(bool value)
 {
     m_drawingToImageBuffer = value;
@@ -239,7 +234,6 @@ bool PlatformContextSkia::isDrawingToImageBuffer() const
 {
     return m_drawingToImageBuffer;
 }
-#endif
 
 void PlatformContextSkia::save()
 {
@@ -248,17 +242,14 @@ void PlatformContextSkia::save()
     m_stateStack.append(m_state->cloneInheritedProperties());
     m_state = &m_stateStack.last();
 
-#if OS(LINUX) || OS(WINDOWS)
     // The clip image only needs to be applied once. Reset the image so that we
     // don't attempt to clip multiple times.
     m_state->m_imageBufferClip.reset();
-#endif
 
     // Save our native canvas.
     canvas()->save();
 }
 
-#if OS(LINUX) || OS(WINDOWS)
 void PlatformContextSkia::beginLayerClippedToImage(const FloatRect& rect,
                                                    const ImageBuffer* imageBuffer)
 {
@@ -287,7 +278,6 @@ void PlatformContextSkia::beginLayerClippedToImage(const FloatRect& rect,
         m_state->m_imageBufferClip = *bitmap;
     }
 }
-#endif
 
 void PlatformContextSkia::clipPathAntiAliased(const SkPath& clipPath)
 {
@@ -306,12 +296,10 @@ void PlatformContextSkia::clipPathAntiAliased(const SkPath& clipPath)
 
 void PlatformContextSkia::restore()
 {
-#if OS(LINUX) || OS(WINDOWS)
     if (!m_state->m_imageBufferClip.empty()) {
         applyClipFromImage(m_state->m_clip, m_state->m_imageBufferClip);
         canvas()->restore();
     }
-#endif
 
     if (!m_state->m_antiAliasClipPaths.isEmpty())
         applyAntiAliasedClipPaths(m_state->m_antiAliasClipPaths);
@@ -337,7 +325,7 @@ void PlatformContextSkia::drawRect(SkRect rect)
         // We do a fill of four rects to simulate the stroke of a border.
         SkColor oldFillColor = m_state->m_fillColor;
 
-        // setFillColor() will set the shader to NULL, so save a ref to it now. 
+        // setFillColor() will set the shader to NULL, so save a ref to it now.
         SkShader* oldFillShader = m_state->m_fillShader;
         oldFillShader->safeRef();
         setFillColor(m_state->m_strokeColor);
@@ -462,7 +450,7 @@ void PlatformContextSkia::setXfermodeMode(SkXfermode::Mode pdm)
 void PlatformContextSkia::setFillColor(SkColor color)
 {
     m_state->m_fillColor = color;
-    setFillShader(NULL);
+    setFillShader(0);
 }
 
 SkDrawLooper* PlatformContextSkia::getDrawLooper() const
@@ -483,7 +471,7 @@ void PlatformContextSkia::setStrokeStyle(StrokeStyle strokeStyle)
 void PlatformContextSkia::setStrokeColor(SkColor strokeColor)
 {
     m_state->m_strokeColor = strokeColor;
-    setStrokeShader(NULL);
+    setStrokeShader(0);
 }
 
 float PlatformContextSkia::getStrokeThickness() const
@@ -559,6 +547,12 @@ SkPath PlatformContextSkia::currentPathInLocalCoordinates() const
     return localPath;
 }
 
+void PlatformContextSkia::canvasClipPath(const SkPath& path)
+{
+    m_state->m_canvasClipApplied = true;
+    m_canvas->clipPath(path);
+}
+
 void PlatformContextSkia::setFillRule(SkPath::FillType fr)
 {
     m_path.setFillType(fr);
@@ -630,7 +624,6 @@ bool PlatformContextSkia::hasImageResamplingHint() const
     return !m_imageResamplingHintSrcSize.isEmpty() && !m_imageResamplingHintDstSize.isEmpty();
 }
 
-#if OS(LINUX) || OS(WINDOWS)
 void PlatformContextSkia::applyClipFromImage(const FloatRect& rect, const SkBitmap& imageBuffer)
 {
     // NOTE: this assumes the image mask contains opaque black for the portions that are to be shown, as such we
@@ -639,7 +632,6 @@ void PlatformContextSkia::applyClipFromImage(const FloatRect& rect, const SkBitm
     paint.setXfermodeMode(SkXfermode::kDstIn_Mode);
     m_canvas->drawBitmap(imageBuffer, SkFloatToScalar(rect.x()), SkFloatToScalar(rect.y()), &paint);
 }
-#endif
 
 void PlatformContextSkia::applyAntiAliasedClipPaths(WTF::Vector<SkPath>& paths)
 {
@@ -678,33 +670,47 @@ void PlatformContextSkia::applyAntiAliasedClipPaths(WTF::Vector<SkPath>& paths)
     m_canvas->restore();
 }
 
-#if USE(ACCELERATED_COMPOSITING)
-class PrepareTextureCallbackImpl : public CanvasLayerChromium::PrepareTextureCallback {
+bool PlatformContextSkia::canAccelerate() const
+{
+    return !m_state->m_fillShader // Can't accelerate with a fill gradient or pattern.
+        && !m_state->m_looper // Can't accelerate with a shadow.
+        && !m_state->m_canvasClipApplied; // Can't accelerate with a clip to path applied.
+}
+
+class WillPublishCallbackImpl : public DrawingBuffer::WillPublishCallback {
 public:
-    static PassOwnPtr<PrepareTextureCallbackImpl> create(PlatformContextSkia* pcs)
+    static PassOwnPtr<WillPublishCallback> create(PlatformContextSkia* pcs)
     {
-        return new PrepareTextureCallbackImpl(pcs);
+        return adoptPtr(new WillPublishCallbackImpl(pcs));
     }
 
-    virtual void willPrepareTexture()
+    virtual void willPublish()
     {
         m_pcs->prepareForHardwareDraw();
     }
+
 private:
-    explicit PrepareTextureCallbackImpl(PlatformContextSkia* pcs) : m_pcs(pcs) {}
+    explicit WillPublishCallbackImpl(PlatformContextSkia* pcs)
+        : m_pcs(pcs)
+    {
+    }
+
     PlatformContextSkia* m_pcs;
 };
-#endif
 
-void PlatformContextSkia::setGraphicsContext3D(GraphicsContext3D* context, const WebCore::IntSize& size)
+void PlatformContextSkia::setSharedGraphicsContext3D(SharedGraphicsContext3D* context, DrawingBuffer* drawingBuffer, const WebCore::IntSize& size)
 {
-    m_useGPU = true;
-    m_gpuCanvas = new GLES2Canvas(context, size);
-    m_uploadTexture.clear();
-#if USE(ACCELERATED_COMPOSITING)
-    CanvasLayerChromium* layer = static_cast<CanvasLayerChromium*>(context->platformLayer());
-    layer->setPrepareTextureCallback(PrepareTextureCallbackImpl::create(this));
-#endif
+    if (context && drawingBuffer) {
+        m_useGPU = true;
+        m_gpuCanvas = new GLES2Canvas(context, drawingBuffer, size);
+        m_uploadTexture.clear();
+        drawingBuffer->setWillPublishCallback(WillPublishCallbackImpl::create(this));
+    } else {
+        syncSoftwareCanvas();
+        m_uploadTexture.clear();
+        m_gpuCanvas.clear();
+        m_useGPU = false;
+    }
 }
 
 void PlatformContextSkia::prepareForSoftwareDraw() const
@@ -725,9 +731,7 @@ void PlatformContextSkia::prepareForSoftwareDraw() const
         // of a compositing operation).
 
         if (m_state->m_xferMode == SkXfermode::kSrcOver_Mode) {
-            // Last drawn on hardware; clear out the canvas.
-            m_canvas->getDevice()->eraseColor(0);
-            // Start compositing into the empty canvas.
+            // Note that we have rendering results in both the hardware and software backing stores.
             m_backingStoreState = Mixed;
         } else {
             readbackHardwareToSoftware();
@@ -780,17 +784,42 @@ void PlatformContextSkia::syncSoftwareCanvas() const
     m_backingStoreState = Software;
 }
 
+void PlatformContextSkia::markDirtyRect(const IntRect& rect)
+{
+    if (!m_useGPU)
+        return;
+
+    switch (m_backingStoreState) {
+    case Software:
+    case Mixed:
+        m_softwareDirtyRect.unite(rect);
+        return;
+    case Hardware:
+        return;
+    default:
+        ASSERT_NOT_REACHED();
+    }
+}
+
 void PlatformContextSkia::uploadSoftwareToHardware(CompositeOperator op) const
 {
     const SkBitmap& bitmap = m_canvas->getDevice()->accessBitmap(false);
     SkAutoLockPixels lock(bitmap);
-    GraphicsContext3D* context = m_gpuCanvas->context();
+    SharedGraphicsContext3D* context = m_gpuCanvas->context();
     if (!m_uploadTexture || m_uploadTexture->tiles().totalSizeX() < bitmap.width() || m_uploadTexture->tiles().totalSizeY() < bitmap.height())
-        m_uploadTexture = Texture::create(context, Texture::BGRA8, bitmap.width(), bitmap.height());
-    m_uploadTexture->load(bitmap.getPixels());
-    IntRect rect(0, 0, bitmap.width(), bitmap.height());
+        m_uploadTexture = context->createTexture(Texture::BGRA8, bitmap.width(), bitmap.height());
+
+    m_uploadTexture->updateSubRect(bitmap.getPixels(), m_softwareDirtyRect);
     AffineTransform identity;
-    gpuCanvas()->drawTexturedRect(m_uploadTexture.get(), rect, rect, identity, 1.0, DeviceColorSpace, op);
+    gpuCanvas()->drawTexturedRect(m_uploadTexture.get(), m_softwareDirtyRect, m_softwareDirtyRect, identity, 1.0, DeviceColorSpace, op);
+    // Clear out the region of the software canvas we just uploaded.
+    m_canvas->save();
+    m_canvas->resetMatrix();
+    SkRect bounds = m_softwareDirtyRect;
+    m_canvas->clipRect(bounds, SkRegion::kReplace_Op);
+    m_canvas->drawARGB(0, 0, 0, 0, SkXfermode::kClear_Mode);
+    m_canvas->restore();
+    m_softwareDirtyRect.setWidth(0); // Clear dirty rect.
 }
 
 void PlatformContextSkia::readbackHardwareToSoftware() const
@@ -799,7 +828,8 @@ void PlatformContextSkia::readbackHardwareToSoftware() const
     SkAutoLockPixels lock(bitmap);
     int width = bitmap.width(), height = bitmap.height();
     OwnArrayPtr<uint32_t> buf(new uint32_t[width]);
-    GraphicsContext3D* context = m_gpuCanvas->context();
+    SharedGraphicsContext3D* context = m_gpuCanvas->context();
+    m_gpuCanvas->bindFramebuffer();
     // Flips the image vertically.
     for (int y = 0; y < height; ++y) {
         uint32_t* pixels = bitmap.getAddr32(0, y);
@@ -814,6 +844,7 @@ void PlatformContextSkia::readbackHardwareToSoftware() const
             }
         }
     }
+    m_softwareDirtyRect.unite(IntRect(0, 0, width, height)); // Mark everything as dirty.
 }
 
 } // namespace WebCore
diff --git a/WebCore/platform/graphics/skia/PlatformContextSkia.h b/WebCore/platform/graphics/skia/PlatformContextSkia.h
index 82edc16..4ba85d1 100644
--- a/WebCore/platform/graphics/skia/PlatformContextSkia.h
+++ b/WebCore/platform/graphics/skia/PlatformContextSkia.h
@@ -1,10 +1,10 @@
 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
- * 
+ *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ -14,7 +14,7 @@
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
@@ -35,7 +35,6 @@
 #include "Noncopyable.h"
 
 #include "SkDashPathEffect.h"
-#include "SkDeque.h"
 #include "SkDrawLooper.h"
 #include "SkPaint.h"
 #include "SkPath.h"
@@ -46,9 +45,10 @@
 namespace WebCore {
 
 enum CompositeOperator;
+class DrawingBuffer;
 class GLES2Canvas;
-class Texture;
 class GraphicsContext3D;
+class Texture;
 
 // This class holds the platform-specific state for GraphicsContext. We put
 // most of our Skia wrappers on this class. In theory, a lot of this stuff could
@@ -78,7 +78,6 @@ public:
     // to the constructor.
     void setCanvas(skia::PlatformCanvas*);
 
-#if OS(WINDOWS)
     // If false we're rendering to a GraphicsContext for a web page, if false
     // we're not (as is the case when rendering to a canvas object).
     // If this is true the contents have not been marked up with the magic
@@ -86,7 +85,6 @@ public:
     // correctly updated.
     void setDrawingToImageBuffer(bool);
     bool isDrawingToImageBuffer() const;
-#endif
 
     void save();
     void restore();
@@ -95,9 +93,7 @@ public:
     // |rect|. This layer is implicitly restored when the next restore is
     // invoked.
     // NOTE: |imageBuffer| may be deleted before the |restore| is invoked.
-#if OS(LINUX) || OS(WINDOWS)
     void beginLayerClippedToImage(const FloatRect&, const ImageBuffer*);
-#endif
     void clipPathAntiAliased(const SkPath&);
 
     // Sets up the common flags on a paint for antialiasing, effects, etc.
@@ -143,6 +139,8 @@ public:
     void addPath(const SkPath&);
     SkPath currentPathInLocalCoordinates() const;
 
+    void canvasClipPath(const SkPath&);
+
     // Returns the fill color. The returned color has it's alpha adjusted
     // by the current alpha.
     SkColor effectiveFillColor() const;
@@ -180,8 +178,10 @@ public:
     void setImageResamplingHint(const IntSize& srcSize, const FloatSize& dstSize);
     void clearImageResamplingHint();
     bool hasImageResamplingHint() const;
+
+    bool canAccelerate() const;
     bool useGPU() { return m_useGPU; }
-    void setGraphicsContext3D(GraphicsContext3D*, const IntSize&);
+    void setSharedGraphicsContext3D(SharedGraphicsContext3D*, DrawingBuffer*, const IntSize&);
     GLES2Canvas* gpuCanvas() const { return m_gpuCanvas.get(); }
 
     // Call these before making a call that manipulates the underlying
@@ -190,13 +190,12 @@ public:
     void prepareForHardwareDraw() const;
     // Call to force the skia::PlatformCanvas to contain all rendering results.
     void syncSoftwareCanvas() const;
+    void markDirtyRect(const IntRect& rect);
 
 private:
-#if OS(LINUX) || OS(WINDOWS)
     // Used when restoring and the state has an image clip. Only shows the pixels in
     // m_canvas that are also in imageBuffer.
     void applyClipFromImage(const FloatRect&, const SkBitmap&);
-#endif
     void applyAntiAliasedClipPaths(WTF::Vector<SkPath>& paths);
 
     void uploadSoftwareToHardware(CompositeOperator) const;
@@ -218,17 +217,16 @@ private:
     // Current path in global coordinates.
     SkPath m_path;
 
-    // Stores image sizes for a hint to compute image resampling modes. 
+    // Stores image sizes for a hint to compute image resampling modes.
     // Values are used in ImageSkia.cpp
     IntSize m_imageResamplingHintSrcSize;
     FloatSize m_imageResamplingHintDstSize;
-#if OS(WINDOWS)
     bool m_drawingToImageBuffer;
-#endif
     bool m_useGPU;
     OwnPtr<GLES2Canvas> m_gpuCanvas;
     mutable enum { None, Software, Mixed, Hardware } m_backingStoreState;
     mutable RefPtr<Texture> m_uploadTexture;
+    mutable IntRect m_softwareDirtyRect;
 };
 
 }