3 files changed, 72 insertions, 16 deletions
diff --git a/Source/WebKit2/UIProcess/mac/BackingStoreMac.mm b/Source/WebKit2/UIProcess/mac/BackingStoreMac.mm
index 979f755..eacfefa 100644
--- a/Source/WebKit2/UIProcess/mac/BackingStoreMac.mm
+++ b/Source/WebKit2/UIProcess/mac/BackingStoreMac.mm
@@ -28,6 +28,7 @@
 #include "CGUtilities.h"
 #include "ShareableBitmap.h"
 #include "UpdateInfo.h"
+#include "WebPageProxy.h"
 #include <WebCore/GraphicsContext.h>
 
 using namespace WebCore;
@@ -36,34 +37,70 @@ namespace WebKit {
 
 void BackingStore::paint(PlatformGraphicsContext context, const IntRect& rect)
 {
-    ASSERT(m_bitmapContext);
+    if (m_cgLayer) {
+        CGContextSaveGState(context);
+        CGContextClipToRect(context, rect);
+
+        CGContextScaleCTM(context, 1, -1);
+        CGContextDrawLayerAtPoint(context, CGPointMake(0, -m_size.height()), m_cgLayer.get());
+
+        CGContextRestoreGState(context);
+        return;
+    }
 
+    ASSERT(m_bitmapContext);
     paintBitmapContext(context, m_bitmapContext.get(), rect.location(), rect);
 }
 
-void BackingStore::incorporateUpdate(const UpdateInfo& updateInfo)
+CGContextRef BackingStore::backingStoreContext()
 {
-    ASSERT(m_size == updateInfo.viewSize);
+    if (m_cgLayer)
+        return CGLayerGetContext(m_cgLayer.get());
 
-    RefPtr<ShareableBitmap> bitmap = ShareableBitmap::create(updateInfo.updateRectBounds.size(), updateInfo.bitmapHandle);
-    if (!bitmap)
-        return;
+    // Try to create a layer.
+    if (CGContextRef containingWindowContext = m_webPageProxy->containingWindowGraphicsContext()) {
+        m_cgLayer.adoptCF(CGLayerCreateWithContext(containingWindowContext, NSSizeToCGSize(m_size), 0));
+        CGContextRef layerContext = CGLayerGetContext(m_cgLayer.get());
+        
+        CGContextSetBlendMode(layerContext, kCGBlendModeCopy);
+
+        // We want the origin to be in the top left corner so flip the backing store context.
+        CGContextTranslateCTM(layerContext, 0, m_size.height());
+        CGContextScaleCTM(layerContext, 1, -1);
+
+        if (m_bitmapContext) {
+            // Paint the contents of the bitmap into the layer context.
+            paintBitmapContext(layerContext, m_bitmapContext.get(), CGPointZero, CGRectMake(0, 0, m_size.width(), m_size.height()));
+            m_bitmapContext = nullptr;
+        }
+
+        return layerContext;
+    }
 
     if (!m_bitmapContext) {
         RetainPtr<CGColorSpaceRef> colorSpace(AdoptCF, CGColorSpaceCreateDeviceRGB());
         
         m_bitmapContext.adoptCF(CGBitmapContextCreate(0, m_size.width(), m_size.height(), 8, m_size.width() * 4, colorSpace.get(), kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host));
-        
+
+        CGContextSetBlendMode(m_bitmapContext.get(), kCGBlendModeCopy);
+
         // We want the origin to be in the top left corner so flip the backing store context.
         CGContextTranslateCTM(m_bitmapContext.get(), 0, m_size.height());
         CGContextScaleCTM(m_bitmapContext.get(), 1, -1);
     }
 
-    scroll(updateInfo.scrollRect, updateInfo.scrollDelta);
+    return m_bitmapContext.get();
+}
+
+void BackingStore::incorporateUpdate(ShareableBitmap* bitmap, const UpdateInfo& updateInfo)
+{
+    CGContextRef context = backingStoreContext();
+
+    scroll(updateInfo.scrollRect, updateInfo.scrollOffset);
 
     IntPoint updateRectLocation = updateInfo.updateRectBounds.location();
 
-    GraphicsContext graphicsContext(m_bitmapContext.get());
+    GraphicsContext graphicsContext(context);
 
     // Paint all update rects.
     for (size_t i = 0; i < updateInfo.updateRects.size(); ++i) {
@@ -75,18 +112,30 @@ void BackingStore::incorporateUpdate(const UpdateInfo& updateInfo)
     }
 }
 
-void BackingStore::scroll(const IntRect& scrollRect, const IntSize& scrollDelta)
+void BackingStore::scroll(const IntRect& scrollRect, const IntSize& scrollOffset)
 {
-    if (scrollDelta.isZero())
+    if (scrollOffset.isZero())
         return;
 
-    CGContextSaveGState(m_bitmapContext.get());
+    if (m_cgLayer) {
+        CGContextRef layerContext = CGLayerGetContext(m_cgLayer.get());
 
-    CGContextClipToRect(m_bitmapContext.get(), scrollRect);
+        // Scroll the layer by painting it into itself with the given offset.
+        CGContextSaveGState(layerContext);
+        CGContextClipToRect(layerContext, scrollRect);
+        CGContextScaleCTM(layerContext, 1, -1);
+        CGContextDrawLayerAtPoint(layerContext, CGPointMake(scrollOffset.width(), -m_size.height() - scrollOffset.height()), m_cgLayer.get());
+        CGContextRestoreGState(layerContext);
 
-    CGPoint destination = CGPointMake(scrollRect.x() + scrollDelta.width(), scrollRect.y() + scrollDelta.height());
-    paintBitmapContext(m_bitmapContext.get(), m_bitmapContext.get(), destination, scrollRect);
+        return;
+    }
+
+    ASSERT(m_bitmapContext);
 
+    CGContextSaveGState(m_bitmapContext.get());
+    CGContextClipToRect(m_bitmapContext.get(), scrollRect);
+    CGPoint destination = CGPointMake(scrollRect.x() + scrollOffset.width(), scrollRect.y() + scrollOffset.height());
+    paintBitmapContext(m_bitmapContext.get(), m_bitmapContext.get(), destination, scrollRect);
     CGContextRestoreGState(m_bitmapContext.get());
 }
 
diff --git a/Source/WebKit2/UIProcess/mac/WebContextMac.mm b/Source/WebKit2/UIProcess/mac/WebContextMac.mm
index ce4c3e6..4d1679f 100644
--- a/Source/WebKit2/UIProcess/mac/WebContextMac.mm
+++ b/Source/WebKit2/UIProcess/mac/WebContextMac.mm
@@ -74,7 +74,8 @@ void WebContext::platformInitializeWebProcess(WebProcessCreationParameters& para
         cachePath = reinterpret_cast<CFStringRef>(NSHomeDirectory());
 
     NSURLCache *urlCache = [NSURLCache sharedURLCache];
-    
+
+    parameters.parentProcessName = [[NSProcessInfo processInfo] processName];    
     parameters.nsURLCachePath = fileSystemRepresentation([(NSString *)cachePath.get() stringByStandardizingPath]);
     parameters.nsURLCacheMemoryCapacity = [urlCache memoryCapacity];
     parameters.nsURLCacheDiskCapacity = [urlCache diskCapacity];
diff --git a/Source/WebKit2/UIProcess/mac/WebPageProxyMac.mm b/Source/WebKit2/UIProcess/mac/WebPageProxyMac.mm
index 36905fb..cd3e6f1 100644
--- a/Source/WebKit2/UIProcess/mac/WebPageProxyMac.mm
+++ b/Source/WebKit2/UIProcess/mac/WebPageProxyMac.mm
@@ -25,6 +25,7 @@
 
 #include "WebPageProxy.h"
 
+#include "PageClient.h"
 #include <WebCore/Language.h>
 #include <wtf/text/StringConcatenate.h>
 
@@ -110,4 +111,9 @@ void WebPageProxy::stopSpeaking()
     [NSApp stopSpeaking:nil];
 }
 
+CGContextRef WebPageProxy::containingWindowGraphicsContext()
+{
+    return m_pageClient->containingWindowGraphicsContext();
+}
+
 } // namespace WebKit