Cleanup Skia related rendering code for raster rendering.

In the existing code we created a sharedBitmap for BaseTiles and
never used it instead opting for createing bitmaps on the stack to
enable partial invalidation. This CL removes the sharedBitmap concept
and instead creates all bitmaps on the stack.

This means that BackedDoubleBufferedTexture no longer needs to have
a bitmap member, but instead simply takes the bitmap from the caller
and uploads it to the appropriate texture. To make this upload clean
we now pass the bitmap via const references instead of pointers.

Change-Id: Ie218c4b4564e5574ca6e404d4857904ab41a3a5c

15 files changed, 108 insertions, 161 deletions

diff --git a/Source/WebCore/Android.mk b/Source/WebCore/Android.mk
index efdfc42..4673b45 100644
--- a/Source/WebCore/Android.mk
+++ b/Source/WebCore/Android.mk
@@ -632,9 +632,9 @@ LOCAL_SRC_FILES := $(LOCAL_SRC_FILES) \
 	platform/graphics/WidthIterator.cpp \
 	\
 	platform/graphics/android/AndroidAnimation.cpp \
-	platform/graphics/android/BackedDoubleBufferedTexture.cpp \
 	platform/graphics/android/BaseLayerAndroid.cpp \
 	platform/graphics/android/BaseTile.cpp \
+	platform/graphics/android/BaseTileTexture.cpp \
 	platform/graphics/android/BitmapAllocatorAndroid.cpp \
 	platform/graphics/android/ClassTracker.cpp \
 	platform/graphics/android/DoubleBufferedTexture.cpp \
diff --git a/Source/WebCore/platform/graphics/android/BaseTile.cpp b/Source/WebCore/platform/graphics/android/BaseTile.cpp
index 4515083..7020208 100644
--- a/Source/WebCore/platform/graphics/android/BaseTile.cpp
+++ b/Source/WebCore/platform/graphics/android/BaseTile.cpp
@@ -95,7 +95,7 @@ void BaseTile::setContents(TiledPage* page, int x, int y)
 
 void BaseTile::reserveTexture()
 {
-    BackedDoubleBufferedTexture* texture = TilesManager::instance()->getAvailableTexture(this);
+    BaseTileTexture* texture = TilesManager::instance()->getAvailableTexture(this);
 
     android::AutoMutex lock(m_atomicSync);
     if (texture && m_texture != texture) {
@@ -105,7 +105,7 @@ void BaseTile::reserveTexture()
     }
 }
 
-bool BaseTile::removeTexture(BackedDoubleBufferedTexture* texture)
+bool BaseTile::removeTexture(BaseTileTexture* texture)
 {
     XLOG("%x removeTexture res: %x... page %x", this, m_texture, m_page);
     // We update atomically, so paintBitmap() can see the correct value
@@ -254,7 +254,7 @@ void BaseTile::paintBitmap()
     // can be updated by other threads without consequence.
     m_atomicSync.lock();
     bool dirty = m_dirty;
-    BackedDoubleBufferedTexture* texture = m_texture;
+    BaseTileTexture* texture = m_texture;
     SkRegion dirtyArea = *m_currentDirtyArea;
     float scale = m_scale;
     const int x = m_x;
@@ -289,7 +289,8 @@ void BaseTile::paintBitmap()
     // TODO: Implement the partial invalidate in Surface Texture Mode
     if (((m_currentDirtyArea == &m_dirtyAreaA) && m_fullRepaintA)
             || ((m_currentDirtyArea == &m_dirtyAreaB) && m_fullRepaintB)
-            || !GLUtils::textureExist(textureInfo, texture->bitmap())
+            || textureInfo->m_width != tileWidth
+            || textureInfo->m_height != tileHeight
             || textureInfo->getSharedTextureMode() == SurfaceTextureMode) {
         fullRepaint = true;
     }
diff --git a/Source/WebCore/platform/graphics/android/BaseTile.h b/Source/WebCore/platform/graphics/android/BaseTile.h
index f58a598..cddaa60 100644
--- a/Source/WebCore/platform/graphics/android/BaseTile.h
+++ b/Source/WebCore/platform/graphics/android/BaseTile.h
@@ -39,7 +39,7 @@ namespace WebCore {
 
 class TextureInfo;
 class TiledPage;
-class BackedDoubleBufferedTexture;
+class BaseTileTexture;
 
 /**
  * An individual tile that is used to construct part of a webpage's BaseLayer of
@@ -74,7 +74,7 @@ public:
     // the only thread-safe function called by the background thread
     void paintBitmap();
     int paintPartialBitmap(SkIRect rect, float tx, float ty,
-                            float scale, BackedDoubleBufferedTexture* texture,
+                            float scale, BaseTileTexture* texture,
                             TextureInfo* textureInfo,
                             TiledPage* tiledPage,
                             bool fullRepaint = false);
@@ -92,10 +92,10 @@ public:
     int x() const { return m_x; }
     int y() const { return m_y; }
     unsigned int lastPaintedPicture() const { return m_lastPaintedPicture; }
-    BackedDoubleBufferedTexture* texture() { return m_texture; }
+    BaseTileTexture* texture() { return m_texture; }
 
     // TextureOwner implementation
-    virtual bool removeTexture(BackedDoubleBufferedTexture* texture);
+    virtual bool removeTexture(BaseTileTexture* texture);
     virtual TiledPage* page() { return m_page; }
 
 private:
@@ -105,7 +105,7 @@ private:
     int m_y;
 
     // The remaining variables can be updated throughout the lifetime of the object
-    BackedDoubleBufferedTexture* m_texture;
+    BaseTileTexture* m_texture;
     float m_scale;
     // used to signal that the that the tile is out-of-date and needs to be redrawn
     bool m_dirty;
diff --git a/Source/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.cpp b/Source/WebCore/platform/graphics/android/BaseTileTexture.cpp
index 0e22103..ee8cebf 100644
--- a/Source/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.cpp
+++ b/Source/WebCore/platform/graphics/android/BaseTileTexture.cpp
@@ -24,7 +24,7 @@
  */
 
 #include "config.h"
-#include "BackedDoubleBufferedTexture.h"
+#include "BaseTileTexture.h"
 
 #include "BaseTile.h"
 #include "ClassTracker.h"
@@ -33,65 +33,38 @@
 #include "TilesManager.h"
 
 #define LOG_NDEBUG 1
-#define LOG_TAG "BackedDoubleBufferedTexture.cpp"
+#define LOG_TAG "BaseTileTexture.cpp"
 #include <utils/Log.h>
 
 namespace WebCore {
 
-BackedDoubleBufferedTexture::BackedDoubleBufferedTexture(uint32_t w, uint32_t h,
-                                                         SkBitmap* bitmap,
-                                                         SkBitmap::Config config)
+BaseTileTexture::BaseTileTexture(uint32_t w, uint32_t h)
     : DoubleBufferedTexture(eglGetCurrentContext(), SurfaceTextureMode)
     , m_usedLevel(-1)
-    , m_config(config)
     , m_owner(0)
     , m_delayedReleaseOwner(0)
     , m_delayedRelease(false)
     , m_busy(false)
 {
     m_size.set(w, h);
-    if (bitmap) {
-        m_bitmap = bitmap;
-        m_sharedBitmap = true;
-        m_canvas = new SkCanvas(*m_bitmap);
-    } else {
-        m_bitmap = 0;
-        m_sharedBitmap = false;
-        m_canvas = 0;
-    }
 
 #ifdef DEBUG_COUNT
-    ClassTracker::instance()->increment("BackedDoubleBufferedTexture");
+    ClassTracker::instance()->increment("BaseTileTexture");
 #endif
 }
 
-SkCanvas* BackedDoubleBufferedTexture::canvas()
-{
-    if (!m_bitmap && !m_sharedBitmap) {
-        m_bitmap = new SkBitmap();
-        m_bitmap->setConfig(m_config, m_size.width(), m_size.height());
-        m_bitmap->allocPixels();
-        m_bitmap->eraseColor(0);
-        m_canvas = new SkCanvas(*m_bitmap);
-    }
-    return m_canvas;
-}
-
-BackedDoubleBufferedTexture::~BackedDoubleBufferedTexture()
+BaseTileTexture::~BaseTileTexture()
 {
-    if (!m_sharedBitmap)
-        delete m_bitmap;
-    delete m_canvas;
     if (m_sharedTextureMode == EglImageMode) {
         SharedTexture* textures[3] = { m_textureA, m_textureB, 0 };
         destroyTextures(textures);
     }
 #ifdef DEBUG_COUNT
-    ClassTracker::instance()->decrement("BackedDoubleBufferedTexture");
+    ClassTracker::instance()->decrement("BaseTileTexture");
 #endif
 }
 
-void BackedDoubleBufferedTexture::destroyTextures(SharedTexture** textures)
+void BaseTileTexture::destroyTextures(SharedTexture** textures)
 {
     int x = 0;
     while (textures[x]) {
@@ -108,7 +81,7 @@ void BackedDoubleBufferedTexture::destroyTextures(SharedTexture** textures)
     }
 }
 
-TextureInfo* BackedDoubleBufferedTexture::producerLock()
+TextureInfo* BaseTileTexture::producerLock()
 {
     m_busyLock.lock();
     m_busy = true;
@@ -116,19 +89,19 @@ TextureInfo* BackedDoubleBufferedTexture::producerLock()
     return DoubleBufferedTexture::producerLock();
 }
 
-void BackedDoubleBufferedTexture::producerRelease()
+void BaseTileTexture::producerRelease()
 {
     DoubleBufferedTexture::producerRelease();
     setNotBusy();
 }
 
-void BackedDoubleBufferedTexture::producerReleaseAndSwap()
+void BaseTileTexture::producerReleaseAndSwap()
 {
     DoubleBufferedTexture::producerReleaseAndSwap();
     setNotBusy();
 }
 
-void BackedDoubleBufferedTexture::setNotBusy()
+void BaseTileTexture::setNotBusy()
 {
     android::Mutex::Autolock lock(m_busyLock);
     m_busy = false;
@@ -142,36 +115,26 @@ void BackedDoubleBufferedTexture::setNotBusy()
     m_busyCond.signal();
 }
 
-bool BackedDoubleBufferedTexture::busy()
+bool BaseTileTexture::busy()
 {
     android::Mutex::Autolock lock(m_busyLock);
     return m_busy;
 }
 
-void BackedDoubleBufferedTexture::producerUpdate(TextureInfo* textureInfo)
+void BaseTileTexture::producerUpdate(TextureInfo* textureInfo, const SkBitmap& bitmap)
 {
-    if (!m_bitmap)
-        return;
-
     // no need to upload a texture since the bitmap is empty
-    if (!m_bitmap->width() && !m_bitmap->height()) {
+    if (!bitmap.width() && !bitmap.height()) {
         producerRelease();
         return;
     }
 
-    GLUtils::paintTextureWithBitmap(textureInfo, m_bitmap, 0, 0, this);
-
-    if (!m_sharedBitmap) {
-        delete m_bitmap;
-        delete m_canvas;
-        m_bitmap = 0;
-        m_canvas = 0;
-    }
+    GLUtils::paintTextureWithBitmap(textureInfo, m_size, bitmap, 0, 0);
 
     producerReleaseAndSwap();
 }
 
-bool BackedDoubleBufferedTexture::acquire(TextureOwner* owner, bool force)
+bool BaseTileTexture::acquire(TextureOwner* owner, bool force)
 {
     if (m_owner == owner) {
         if (m_delayedRelease) {
@@ -184,7 +147,7 @@ bool BackedDoubleBufferedTexture::acquire(TextureOwner* owner, bool force)
     return setOwner(owner, force);
 }
 
-bool BackedDoubleBufferedTexture::tryAcquire(TextureOwner* owner, TiledPage* currentPage, TiledPage* nextPage)
+bool BaseTileTexture::tryAcquire(TextureOwner* owner, TiledPage* currentPage, TiledPage* nextPage)
 {
     m_busyLock.lock();
     if (!m_busy
@@ -198,7 +161,7 @@ bool BackedDoubleBufferedTexture::tryAcquire(TextureOwner* owner, TiledPage* cur
     return false;
 }
 
-bool BackedDoubleBufferedTexture::setOwner(TextureOwner* owner, bool force)
+bool BaseTileTexture::setOwner(TextureOwner* owner, bool force)
 {
     // if the writable texture is busy (i.e. currently being written to) then we
     // can't change the owner out from underneath that texture
@@ -215,7 +178,7 @@ bool BackedDoubleBufferedTexture::setOwner(TextureOwner* owner, bool force)
         // first and paintBitmapGL() will bail out, or we execute it after,
         // and paintBitmapGL() will mark the texture as busy before
         // relinquishing the lock. LayerAndroid::removeTexture() will call
-        // BackedDoubleBufferedTexture::release(), which will then do nothing
+        // BaseTileTexture::release(), which will then do nothing
         // if the texture is busy and we then don't return true.
         bool proceed = true;
         if (m_owner && m_owner != owner)
@@ -229,7 +192,7 @@ bool BackedDoubleBufferedTexture::setOwner(TextureOwner* owner, bool force)
     return false;
 }
 
-bool BackedDoubleBufferedTexture::release(TextureOwner* owner)
+bool BaseTileTexture::release(TextureOwner* owner)
 {
     android::Mutex::Autolock lock(m_busyLock);
     if (m_owner != owner)
@@ -244,7 +207,7 @@ bool BackedDoubleBufferedTexture::release(TextureOwner* owner)
     return true;
 }
 
-void BackedDoubleBufferedTexture::setTile(TextureInfo* info, int x, int y,
+void BaseTileTexture::setTile(TextureInfo* info, int x, int y,
                                           float scale, unsigned int pictureCount)
 {
     TextureTileInfo* textureInfo = m_texturesInfo.get(getWriteableTexture());
@@ -258,7 +221,7 @@ void BackedDoubleBufferedTexture::setTile(TextureInfo* info, int x, int y,
     m_texturesInfo.set(getWriteableTexture(), textureInfo);
 }
 
-bool BackedDoubleBufferedTexture::readyFor(BaseTile* baseTile)
+bool BaseTileTexture::readyFor(BaseTile* baseTile)
 {
     TextureTileInfo* info = m_texturesInfo.get(getReadableTexture());
     if (info &&
diff --git a/Source/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.h b/Source/WebCore/platform/graphics/android/BaseTileTexture.h
index 89ea771..0a7534a 100644
--- a/Source/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.h
+++ b/Source/WebCore/platform/graphics/android/BaseTileTexture.h
@@ -23,8 +23,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef BackedDoubleBufferedTexture_h
-#define BackedDoubleBufferedTexture_h
+#ifndef BaseTileTexture_h
+#define BaseTileTexture_h
 
 #include "DoubleBufferedTexture.h"
 #include "GLWebViewState.h"
@@ -57,14 +57,12 @@ class TextureTileInfo {
 };
 
 // DoubleBufferedTexture using a SkBitmap as backing mechanism
-class BackedDoubleBufferedTexture : public DoubleBufferedTexture {
+class BaseTileTexture : public DoubleBufferedTexture {
 public:
     // This object is to be constructed on the consumer's thread and must have
     // a width and height greater than 0.
-    BackedDoubleBufferedTexture(uint32_t w, uint32_t h,
-                                SkBitmap* bitmap = 0,
-                                SkBitmap::Config config = SkBitmap::kARGB_8888_Config);
-    virtual ~BackedDoubleBufferedTexture();
+    BaseTileTexture(uint32_t w, uint32_t h);
+    virtual ~BaseTileTexture();
 
     // these functions override their parent
     virtual TextureInfo* producerLock();
@@ -73,8 +71,7 @@ public:
 
     // updates the texture with current bitmap and releases (and if needed also
     // swaps) the texture.
-    virtual void producerUpdate(TextureInfo* textureInfo);
-    void producerUpdate(TextureInfo* textureInfo, SkBitmap* bitmap, SkIRect& rect);
+    virtual void producerUpdate(TextureInfo* textureInfo, const SkBitmap& bitmap);
 
     // The level can be one of the following values:
     //  * -1 for an unused texture.
@@ -97,8 +94,6 @@ public:
     // private member accessor functions
     TextureOwner* owner() { return m_owner; } // only used by the consumer thread
     TextureOwner* delayedReleaseOwner() { return m_delayedReleaseOwner; }
-    SkCanvas* canvas(); // only used by the producer thread
-    SkBitmap* bitmap() { return m_bitmap; }
 
     bool busy();
     void setNotBusy();
@@ -114,10 +109,7 @@ protected:
 private:
     void destroyTextures(SharedTexture** textures);
 
-    SkBitmap* m_bitmap;
-    bool m_sharedBitmap;
     SkSize m_size;
-    SkCanvas* m_canvas;
     int m_usedLevel;
     SkBitmap::Config m_config;
     TextureOwner* m_owner;
@@ -142,4 +134,4 @@ private:
 
 } // namespace WebCore
 
-#endif // BackedDoubleBufferedTexture_h
+#endif // BaseTileTexture_h
diff --git a/Source/WebCore/platform/graphics/android/GLUtils.cpp b/Source/WebCore/platform/graphics/android/GLUtils.cpp
index 29608cf..e32f1e9 100644
--- a/Source/WebCore/platform/graphics/android/GLUtils.cpp
+++ b/Source/WebCore/platform/graphics/android/GLUtils.cpp
@@ -336,45 +336,36 @@ GLuint GLUtils::createSampleTexture()
     return texture;
 }
 
-bool GLUtils::textureExist(TextureInfo* textureInfo, const SkBitmap* bitmap)
-{
-    if (!bitmap)
-        return false;
-
-    if (!bitmap->width() || !bitmap->height())
-        return false;
-
-    if (textureInfo->m_width == bitmap->width()
-        && textureInfo->m_height == bitmap->height())
-        return true;
-
-    return false;
-}
-
 void GLUtils::paintTextureWithBitmap(TextureInfo* textureInfo,
-                                     SkBitmap* bitmap,
-                                     int x,
-                                     int y,
-                                     BackedDoubleBufferedTexture* texture)
+                                     const SkSize& requiredSize,
+                                     const SkBitmap& bitmap,
+                                     int x, int y)
 {
     SharedTextureMode mode = textureInfo->getSharedTextureMode();
-    if (textureExist(textureInfo, texture->bitmap())) {
+    if (requiredSize.equals(textureInfo->m_width, textureInfo->m_height)) {
         if (mode == EglImageMode)
-            GLUtils::updateTextureWithBitmap(textureInfo->m_textureId, x, y, *bitmap);
+            GLUtils::updateTextureWithBitmap(textureInfo->m_textureId, x, y, bitmap);
         else if (mode == SurfaceTextureMode)
-            GLUtils::updateSurfaceTextureWithBitmap(textureInfo, x, y, *bitmap);
+            GLUtils::updateSurfaceTextureWithBitmap(textureInfo, x, y, bitmap);
     } else {
+
+        if (!requiredSize.equals(bitmap.width(), bitmap.height())) {
+            XLOG("The bitmap size (%d,%d) does not equal the texture size (%d,%d)",
+                    bitmap.width(), bitmap.height(),
+                    requiredSize.width(), requiredSize.height());
+        }
+
         if (mode == EglImageMode)
-            GLUtils::createTextureWithBitmap(textureInfo->m_textureId, *bitmap);
+            GLUtils::createTextureWithBitmap(textureInfo->m_textureId, bitmap);
         else if (mode == SurfaceTextureMode)
-            GLUtils::createSurfaceTextureWithBitmap(textureInfo, *bitmap);
+            GLUtils::createSurfaceTextureWithBitmap(textureInfo, bitmap);
 
-        textureInfo->m_width = bitmap->width();
-        textureInfo->m_height = bitmap->height();
+        textureInfo->m_width = bitmap.width();
+        textureInfo->m_height = bitmap.height();
     }
 }
 
-void GLUtils::createSurfaceTextureWithBitmap(TextureInfo* texture, SkBitmap& bitmap, GLint filter)
+void GLUtils::createSurfaceTextureWithBitmap(TextureInfo* texture, const SkBitmap& bitmap, GLint filter)
 {
     sp<android::SurfaceTexture> surfaceTexture = texture->m_surfaceTexture;
     sp<ANativeWindow> ANW = texture->m_ANW;
@@ -394,7 +385,7 @@ void GLUtils::createSurfaceTextureWithBitmap(TextureInfo* texture, SkBitmap& bit
     updateSurfaceTextureWithBitmap(texture, 0, 0, bitmap, filter);
 }
 
-void GLUtils::updateSurfaceTextureWithBitmap(TextureInfo* texture, int x, int y, SkBitmap& bitmap, GLint filter)
+void GLUtils::updateSurfaceTextureWithBitmap(TextureInfo* texture, int x, int y, const SkBitmap& bitmap, GLint filter)
 {
     sp<android::SurfaceTexture> surfaceTexture = texture->m_surfaceTexture;
     sp<ANativeWindow> ANW = texture->m_ANW;
@@ -431,7 +422,7 @@ void GLUtils::updateSurfaceTextureWithBitmap(TextureInfo* texture, int x, int y,
     checkSurfaceTextureError("queueBuffer", status);
 }
 
-void GLUtils::createTextureWithBitmap(GLuint texture, SkBitmap& bitmap, GLint filter)
+void GLUtils::createTextureWithBitmap(GLuint texture, const SkBitmap& bitmap, GLint filter)
 {
     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
     glBindTexture(GL_TEXTURE_2D, texture);
@@ -462,7 +453,7 @@ void GLUtils::createTextureWithBitmap(GLuint texture, SkBitmap& bitmap, GLint fi
     glDeleteFramebuffers(1, &fboID);
 }
 
-void GLUtils::updateTextureWithBitmap(GLuint texture, int x, int y, SkBitmap& bitmap, GLint filter)
+void GLUtils::updateTextureWithBitmap(GLuint texture, int x, int y, const SkBitmap& bitmap, GLint filter)
 {
     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
     glBindTexture(GL_TEXTURE_2D, texture);
diff --git a/Source/WebCore/platform/graphics/android/GLUtils.h b/Source/WebCore/platform/graphics/android/GLUtils.h
index 85656f1..a015136 100644
--- a/Source/WebCore/platform/graphics/android/GLUtils.h
+++ b/Source/WebCore/platform/graphics/android/GLUtils.h
@@ -28,9 +28,9 @@
 
 #if USE(ACCELERATED_COMPOSITING)
 
-#include "BackedDoubleBufferedTexture.h"
 #include "SkBitmap.h"
 #include "SkMatrix.h"
+#include "SkSize.h"
 #include "TextureInfo.h"
 #include "TransformationMatrix.h"
 #include <EGL/egl.h>
@@ -64,16 +64,15 @@ public:
     static void deleteTexture(GLuint* texture);
     static GLuint createSampleColorTexture(int r, int g, int b);
     static GLuint createSampleTexture();
-    static void createTextureWithBitmap(GLuint texture, SkBitmap& bitmap, GLint filter = GL_LINEAR);
-    static void updateTextureWithBitmap(GLuint texture, int x, int y, SkBitmap& bitmap, GLint filter = GL_LINEAR);
+    static void createTextureWithBitmap(GLuint texture, const SkBitmap& bitmap, GLint filter = GL_LINEAR);
+    static void updateTextureWithBitmap(GLuint texture, int x, int y, const SkBitmap& bitmap, GLint filter = GL_LINEAR);
     static void createEGLImageFromTexture(GLuint texture, EGLImageKHR* image);
     static void createTextureFromEGLImage(GLuint texture, EGLImageKHR image, GLint filter = GL_LINEAR);
 
-    static bool textureExist(TextureInfo* textureInfo, const SkBitmap* bitmap);
-    static void paintTextureWithBitmap(TextureInfo* textureInfo, SkBitmap* bitmap, int x, int y, BackedDoubleBufferedTexture* texture);
+    static void paintTextureWithBitmap(TextureInfo* textureInfo, const SkSize& requiredSize, const SkBitmap& bitmap, int x, int y);
 
-    static void createSurfaceTextureWithBitmap(TextureInfo* texture, SkBitmap& bitmap, GLint filter  = GL_LINEAR);
-    static void updateSurfaceTextureWithBitmap(TextureInfo* texture, int x, int y, SkBitmap& bitmap, GLint filter  = GL_LINEAR);
+    static void createSurfaceTextureWithBitmap(TextureInfo* texture, const SkBitmap& bitmap, GLint filter  = GL_LINEAR);
+    static void updateSurfaceTextureWithBitmap(TextureInfo* texture, int x, int y, const SkBitmap& bitmap, GLint filter  = GL_LINEAR);
 };
 
 } // namespace WebCore
diff --git a/Source/WebCore/platform/graphics/android/LayerAndroid.cpp b/Source/WebCore/platform/graphics/android/LayerAndroid.cpp
index 74b246f..e90829a 100644
--- a/Source/WebCore/platform/graphics/android/LayerAndroid.cpp
+++ b/Source/WebCore/platform/graphics/android/LayerAndroid.cpp
@@ -163,7 +163,7 @@ LayerAndroid::LayerAndroid(SkPicture* picture) : SkLayer(),
 #endif
 }
 
-bool LayerAndroid::removeTexture(BackedDoubleBufferedTexture* aTexture)
+bool LayerAndroid::removeTexture(BaseTileTexture* aTexture)
 {
     LayerTexture* texture = static_cast<LayerTexture*>(aTexture);
     android::AutoMutex lock(m_atomicSync);
@@ -1051,14 +1051,21 @@ void LayerAndroid::paintBitmapGL()
     }
 
     XLOG("LayerAndroid %d %x (%.2f, %.2f) paintBitmapGL WE ARE PAINTING", uniqueId(), this, getWidth(), getHeight());
-    SkCanvas* canvas = texture->canvas();
+
+    SkBitmap bitmap;
+    bitmap.setConfig(SkBitmap::kARGB_8888_Config, texture->getSize().width(), texture->getSize().height());
+    bitmap.allocPixels();
+
+    SkCanvas canvas(bitmap);
+    canvas.drawARGB(0, 0, 0, 0, SkXfermode::kClear_Mode);
+
     float scale = texture->scale();
 
     IntRect textureRect = texture->rect();
-    canvas->drawARGB(0, 0, 0, 0, SkXfermode::kClear_Mode);
+
 
     if (m_contentsImage) {
-        contentDraw(canvas);
+        contentDraw(&canvas);
     } else {
         SkPicture picture;
         SkCanvas* nCanvas = picture.beginRecording(textureRect.width(),
@@ -1067,9 +1074,9 @@ void LayerAndroid::paintBitmapGL()
         nCanvas->translate(-textureRect.x(), -textureRect.y());
         contentDraw(nCanvas);
         picture.endRecording();
-        picture.draw(canvas);
+        picture.draw(&canvas);
     }
-    extraDraw(canvas);
+    extraDraw(&canvas);
 
     m_atomicSync.lock();
     texture->setTextureInfoFor(this);
@@ -1078,7 +1085,7 @@ void LayerAndroid::paintBitmapGL()
     m_requestSent = false;
 
     XLOG("LayerAndroid %d paintBitmapGL PAINTING DONE, updating the texture", uniqueId());
-    texture->producerUpdate(textureInfo);
+    texture->producerUpdate(textureInfo, bitmap);
 
     m_atomicSync.unlock();
 
diff --git a/Source/WebCore/platform/graphics/android/LayerAndroid.h b/Source/WebCore/platform/graphics/android/LayerAndroid.h
index fe41e35..551e020 100644
--- a/Source/WebCore/platform/graphics/android/LayerAndroid.h
+++ b/Source/WebCore/platform/graphics/android/LayerAndroid.h
@@ -84,7 +84,7 @@ struct SkLength {
 namespace WebCore {
 
 class AndroidAnimation;
-class BackedDoubleBufferedTexture;
+class BaseTileTexture;
 class LayerAndroidFindState;
 class RenderLayer;
 class TiledPage;
@@ -98,7 +98,7 @@ public:
     virtual ~LayerAndroid();
 
     // TextureOwner methods
-    virtual bool removeTexture(BackedDoubleBufferedTexture* texture);
+    virtual bool removeTexture(BaseTileTexture* texture);
 
     LayerTexture* texture() { return m_reservedTexture; }
     virtual TiledPage* page() { return 0; }
diff --git a/Source/WebCore/platform/graphics/android/LayerTexture.h b/Source/WebCore/platform/graphics/android/LayerTexture.h
index be3594f..7a6c369 100644
--- a/Source/WebCore/platform/graphics/android/LayerTexture.h
+++ b/Source/WebCore/platform/graphics/android/LayerTexture.h
@@ -26,17 +26,16 @@
 #ifndef LayerTexture_h
 #define LayerTexture_h
 
-#include "BackedDoubleBufferedTexture.h"
+#include "BaseTileTexture.h"
 #include "ClassTracker.h"
 #include "IntRect.h"
 
 namespace WebCore {
 
-class LayerTexture : public BackedDoubleBufferedTexture {
+class LayerTexture : public BaseTileTexture {
  public:
-    LayerTexture(uint32_t w, uint32_t h,
-                 SkBitmap::Config config = SkBitmap::kARGB_8888_Config)
-        : BackedDoubleBufferedTexture(w, h, 0, config)
+    LayerTexture(uint32_t w, uint32_t h)
+        : BaseTileTexture(w, h)
         , m_layerId(0)
         , m_scale(1)
         , m_ready(false)
diff --git a/Source/WebCore/platform/graphics/android/RasterRenderer.cpp b/Source/WebCore/platform/graphics/android/RasterRenderer.cpp
index 04eae7c..c1fcbcb 100644
--- a/Source/WebCore/platform/graphics/android/RasterRenderer.cpp
+++ b/Source/WebCore/platform/graphics/android/RasterRenderer.cpp
@@ -87,7 +87,7 @@ RasterRenderer::~RasterRenderer()
 }
 
 void RasterRenderer::drawTileInfo(SkCanvas* canvas,
-                            BackedDoubleBufferedTexture* texture,
+                            BaseTileTexture* texture,
                             TiledPage* tiledPage,
                             int x, int y, float scale,
                             int pictureCount)
@@ -120,7 +120,7 @@ void RasterRenderer::drawTileInfo(SkCanvas* canvas,
 }
 
 int RasterRenderer::renderContent(int x, int y, SkIRect rect, float tx, float ty,
-                            float scale, BackedDoubleBufferedTexture* texture,
+                            float scale, BaseTileTexture* texture,
                             TextureInfo* textureInfo,
                             TiledPage* tiledPage, bool fullRepaint)
 {
@@ -177,7 +177,7 @@ int RasterRenderer::renderContent(int x, int y, SkIRect rect, float tx, float ty
 
     if (measurePerf)
         m_perfMon.start(TAG_UPDATE_TEXTURE);
-    GLUtils::paintTextureWithBitmap(textureInfo, &bitmap, rect.fLeft, rect.fTop, texture);
+    GLUtils::paintTextureWithBitmap(textureInfo, texture->getSize(), bitmap, rect.fLeft, rect.fTop);
     if (measurePerf)
         m_perfMon.stop(TAG_UPDATE_TEXTURE);
 
diff --git a/Source/WebCore/platform/graphics/android/RasterRenderer.h b/Source/WebCore/platform/graphics/android/RasterRenderer.h
index 88832f6..efe1bd8 100644
--- a/Source/WebCore/platform/graphics/android/RasterRenderer.h
+++ b/Source/WebCore/platform/graphics/android/RasterRenderer.h
@@ -35,7 +35,7 @@ class SkCanvas;
 
 namespace WebCore {
 
-class BackedDoubleBufferedTexture;
+class BaseTileTexture;
 class TextureInfo;
 class TiledPage;
 
@@ -48,12 +48,12 @@ public:
     ~RasterRenderer();
 
     void drawTileInfo(SkCanvas* canvas,
-                      BackedDoubleBufferedTexture* texture,
+                      BaseTileTexture* texture,
                       TiledPage* tiledPage,
                       int x, int y, float scale, int pictureCount);
 
     int renderContent(int x, int y, SkIRect rect, float tx, float ty,
-                      float scale, BackedDoubleBufferedTexture* texture,
+                      float scale, BaseTileTexture* texture,
                       TextureInfo* textureInfo,
                       TiledPage* tiledPage,
                       bool fullRepaint);
diff --git a/Source/WebCore/platform/graphics/android/TextureOwner.h b/Source/WebCore/platform/graphics/android/TextureOwner.h
index aebbf90..bd3a291 100644
--- a/Source/WebCore/platform/graphics/android/TextureOwner.h
+++ b/Source/WebCore/platform/graphics/android/TextureOwner.h
@@ -29,12 +29,12 @@
 namespace WebCore {
 
 class TiledPage;
-class BackedDoubleBufferedTexture;
+class BaseTileTexture;
 
 class TextureOwner {
 public:
     virtual ~TextureOwner() { }
-    virtual bool removeTexture(BackedDoubleBufferedTexture* texture) = 0;
+    virtual bool removeTexture(BaseTileTexture* texture) = 0;
     virtual TiledPage* page() = 0;
 };
 
diff --git a/Source/WebCore/platform/graphics/android/TilesManager.cpp b/Source/WebCore/platform/graphics/android/TilesManager.cpp
index 0e91dc7..b4df0a1 100644
--- a/Source/WebCore/platform/graphics/android/TilesManager.cpp
+++ b/Source/WebCore/platform/graphics/android/TilesManager.cpp
@@ -96,10 +96,6 @@ TilesManager::TilesManager()
 {
     XLOG("TilesManager ctor");
     m_textures.reserveCapacity(MAX_TEXTURE_ALLOCATION);
-    m_tilesBitmap = new SkBitmap();
-    m_tilesBitmap->setConfig(SkBitmap::kARGB_8888_Config, tileWidth(), tileHeight());
-    m_tilesBitmap->allocPixels();
-    m_tilesBitmap->eraseColor(0);
     m_pixmapsGenerationThread = new TexturesGenerator();
     m_pixmapsGenerationThread->run("TexturesGenerator");
 }
@@ -110,12 +106,12 @@ void TilesManager::allocateTiles()
     XLOG("%d tiles to allocate (%d textures planned)", nbTexturesToAllocate, m_maxTextureCount);
     int nbTexturesAllocated = 0;
     for (int i = 0; i < nbTexturesToAllocate; i++) {
-        BackedDoubleBufferedTexture* texture = new BackedDoubleBufferedTexture(
-            tileWidth(), tileHeight(), m_tilesBitmap);
+        BaseTileTexture* texture = new BaseTileTexture(
+            tileWidth(), tileHeight());
         // the atomic load ensures that the texture has been fully initialized
         // before we pass a pointer for other threads to operate on
-        BackedDoubleBufferedTexture* loadedTexture =
-            reinterpret_cast<BackedDoubleBufferedTexture*>(
+        BaseTileTexture* loadedTexture =
+            reinterpret_cast<BaseTileTexture*>(
             android_atomic_acquire_load(reinterpret_cast<int32_t*>(&texture)));
         m_textures.append(loadedTexture);
         nbTexturesAllocated++;
@@ -128,7 +124,7 @@ void TilesManager::printTextures()
 #ifdef DEBUG
     XLOG("++++++");
     for (unsigned int i = 0; i < m_textures.size(); i++) {
-        BackedDoubleBufferedTexture* texture = m_textures[i];
+        BaseTileTexture* texture = m_textures[i];
         BaseTile* o = 0;
         if (texture->owner())
             o = (BaseTile*) texture->owner();
@@ -150,7 +146,7 @@ void TilesManager::resetTextureUsage(TiledPage* page)
 {
     android::Mutex::Autolock lock(m_texturesLock);
     for (unsigned int i = 0; i < m_textures.size(); i++) {
-        BackedDoubleBufferedTexture* texture = m_textures[i];
+        BaseTileTexture* texture = m_textures[i];
         TextureOwner* owner = texture->owner();
         if (owner) {
             if (owner->page() == page)
@@ -159,7 +155,7 @@ void TilesManager::resetTextureUsage(TiledPage* page)
     }
 }
 
-BackedDoubleBufferedTexture* TilesManager::getAvailableTexture(BaseTile* owner)
+BaseTileTexture* TilesManager::getAvailableTexture(BaseTile* owner)
 {
     android::Mutex::Autolock lock(m_texturesLock);
 
@@ -177,11 +173,11 @@ BackedDoubleBufferedTexture* TilesManager::getAvailableTexture(BaseTile* owner)
     //  3. return any texture not used by the tile's page or the page's sibiling
     //
     // The texture level indicates a tiles closeness to the current viewport
-    BackedDoubleBufferedTexture* farthestTexture = 0;
+    BaseTileTexture* farthestTexture = 0;
     int farthestTextureLevel = 0;
     const unsigned int max = m_textures.size();
     for (unsigned int i = 0; i < max; i++) {
-        BackedDoubleBufferedTexture* texture = m_textures[i];
+        BaseTileTexture* texture = m_textures[i];
         if (texture->usedLevel() == -1) { // found an unused texture, grab it
             farthestTexture = texture;
             break;
@@ -204,7 +200,7 @@ BackedDoubleBufferedTexture* TilesManager::getAvailableTexture(BaseTile* owner)
     TiledPage* currentPage = owner->page();
     TiledPage* nextPage = currentPage->sibling();
     for (unsigned int i = 0; i < max; i++) {
-        BackedDoubleBufferedTexture* texture = m_textures[i];
+        BaseTileTexture* texture = m_textures[i];
         if (texture->tryAcquire(owner, currentPage, nextPage)) {
             XLOG("grab a texture that wasn't ours, (%x != %x) at %d => texture %x",
                  owner->page(), texture->owner()->page(), i, texture);
diff --git a/Source/WebCore/platform/graphics/android/TilesManager.h b/Source/WebCore/platform/graphics/android/TilesManager.h
index e43afed..5237c14 100644
--- a/Source/WebCore/platform/graphics/android/TilesManager.h
+++ b/Source/WebCore/platform/graphics/android/TilesManager.h
@@ -28,8 +28,8 @@
 
 #if USE(ACCELERATED_COMPOSITING)
 
-#include "BackedDoubleBufferedTexture.h"
 #include "BaseTile.h"
+#include "BaseTileTexture.h"
 #include "LayerAndroid.h"
 #include "LayerTexture.h"
 #include "ShaderProgram.h"
@@ -79,7 +79,7 @@ public:
     ShaderProgram* shader() { return &m_shader; }
     VideoLayerManager* videoLayerManager() { return &m_videoLayerManager; }
 
-    BackedDoubleBufferedTexture* getAvailableTexture(BaseTile* owner);
+    BaseTileTexture* getAvailableTexture(BaseTile* owner);
 
     void printLayersTextures(const char* s);
     void cleanupLayersTextures(LayerAndroid* layer, bool forceCleanup = false);
@@ -134,7 +134,7 @@ private:
             m_generatorReadyCond.wait(m_generatorLock);
     }
 
-    Vector<BackedDoubleBufferedTexture*> m_textures;
+    Vector<BaseTileTexture*> m_textures;
     Vector<LayerTexture*> m_layersTextures;
 
     unsigned int m_layersMemoryUsage;
@@ -156,7 +156,6 @@ private:
 
     ShaderProgram m_shader;
     VideoLayerManager m_videoLayerManager;
-    SkBitmap* m_tilesBitmap;
 };
 
 } // namespace WebCore