Use SkImage as a backing store for copying 2d Contexts to ImageBitmaps.

Source/core/platform/graphics/ImageBuffer.cpp

Index: Source/core/platform/graphics/ImageBuffer.cpp
diff --git a/Source/core/platform/graphics/ImageBuffer.cpp b/Source/core/platform/graphics/ImageBuffer.cpp
index d130b56eeb7ca153613677805429016c17297ccb..3b32828787952c01d9c604c2099acb354510111d 100644
--- a/Source/core/platform/graphics/ImageBuffer.cpp
+++ b/Source/core/platform/graphics/ImageBuffer.cpp
@@ -63,7 +63,7 @@ using namespace std;
 
 namespace WebCore {
 
-static SkCanvas* createAcceleratedCanvas(const IntSize& size, OwnPtr<Canvas2DLayerBridge>* outLayerBridge, OpacityMode opacityMode)
+SkCanvas* ImageBuffer::createAcceleratedCanvas(const IntSize& size, OwnPtr<Canvas2DLayerBridge>* outLayerBridge, OpacityMode opacityMode)
 {
     RefPtr<GraphicsContext3D> context3D = SharedGraphicsContext3D::get();
     if (!context3D)
@@ -78,21 +78,28 @@ static SkCanvas* createAcceleratedCanvas(const IntSize& size, OwnPtr<Canvas2DLay
     info.fHeight = size.height();
     info.fColorType = SkImage::kPMColor_ColorType;
     info.fAlphaType = SkImage::kPremul_AlphaType;
-    SkAutoTUnref<SkSurface> surface(SkSurface::NewRenderTarget(context3D->grContext(), info));
-    if (!surface.get())
+    m_surface = adoptRef(SkSurface::NewRenderTarget(context3D->grContext(), info));
+    if (!m_surface.get())
         return 0;
-    SkDeferredCanvas* canvas = new SkDeferredCanvas(surface.get());
+    SkDeferredCanvas* canvas = new SkDeferredCanvas(m_surface.get());
     *outLayerBridge = Canvas2DLayerBridge::create(context3D.release(), canvas, bridgeOpacityMode);
     // If canvas buffer allocation failed, debug build will have asserted
     // For release builds, we must verify whether the device has a render target
     return canvas;
 }
 
-static SkCanvas* createNonPlatformCanvas(const IntSize& size)
+SkCanvas* ImageBuffer::createNonPlatformCanvas(const IntSize& size)
 {
-    SkAutoTUnref<SkDevice> device(new SkDevice(SkBitmap::kARGB_8888_Config, size.width(), size.height()));
-    SkPixelRef* pixelRef = device->accessBitmap(false).pixelRef();
-    return pixelRef ? new SkCanvas(device) : 0;
+    SkImage::Info info;
+    info.fWidth = size.width();
+    info.fHeight = size.height();
+    info.fColorType = SkImage::kPMColor_ColorType;
+    info.fAlphaType = SkImage::kPremul_AlphaType;
+    m_surface = SkSurface::NewRaster(info);
+    if (!m_surface.get())
+        return 0;
+    SkCanvas* canvas = m_surface->getCanvas();
+    return canvas;
 }
 
 PassOwnPtr<ImageBuffer> ImageBuffer::createCompatibleBuffer(const IntSize& size, float resolutionScale, const GraphicsContext* context, bool hasAlpha)
@@ -195,6 +202,13 @@ static SkBitmap deepSkBitmapCopy(const SkBitmap& bitmap)
     return tmp;
 }
 
+SkImage* ImageBuffer::imageSnapshot() const
+{
+    if (!m_surface.get())
+        return 0;
+    return m_surface->newImageSnapshot();
+}
+
 PassRefPtr<Image> ImageBuffer::copyImage(BackingStoreCopy copyBehavior, ScaleBehavior) const
 {
     const SkBitmap& bitmap = *context()->bitmap();