Refactoring ImageBuffer to decouple it from Canvas2DLayerBridge

Source/core/rendering/FilterEffectRenderer.cpp

Index: Source/core/rendering/FilterEffectRenderer.cpp
diff --git a/Source/core/rendering/FilterEffectRenderer.cpp b/Source/core/rendering/FilterEffectRenderer.cpp
index a4e007a87e22ad66e9924dcc302a180b43cca1a8..ff60e9b0d76bafa0a793130f70f85b16a2c9b00a 100644
--- a/Source/core/rendering/FilterEffectRenderer.cpp
+++ b/Source/core/rendering/FilterEffectRenderer.cpp
@@ -40,6 +40,7 @@
 #include "platform/FloatConversion.h"
 #include "platform/LengthFunctions.h"
 #include "platform/graphics/ColorSpace.h"
+#include "platform/graphics/UnacceleratedImageBufferSurface.h"
 #include "platform/graphics/filters/FEColorMatrix.h"
 #include "platform/graphics/filters/FEComponentTransfer.h"
 #include "platform/graphics/filters/FEDropShadow.h"
@@ -48,6 +49,7 @@
 #include "platform/graphics/filters/custom/CustomFilterValidatedProgram.h"
 #include "platform/graphics/filters/custom/FECustomFilter.h"
 #include "platform/graphics/filters/custom/ValidatedCustomFilterOperation.h"
+#include "platform/graphics/gpu/AcceleratedImageBufferSurface.h"
 #include "wtf/MathExtras.h"
 #include <algorithm>
 
@@ -311,8 +313,16 @@ void FilterEffectRenderer::allocateBackingStoreIfNeeded()
     // buffer if we have not yet done so.
     if (!m_graphicsBufferAttached) {
         IntSize logicalSize(m_sourceDrawingRegion.width(), m_sourceDrawingRegion.height());
-        if (!sourceImage() || sourceImage()->logicalSize() != logicalSize)
-            setSourceImage(ImageBuffer::create(logicalSize, 1, renderingMode()));
+        if (!sourceImage() || sourceImage()->size() != logicalSize) {
+            OwnPtr<ImageBufferSurface> surface;
+            if (isAccelerated()) {
+                surface = adoptPtr(new AcceleratedImageBufferSurface(logicalSize));
+            }
+            if (!surface || !surface->isValid()) {
+                surface = adoptPtr(new UnacceleratedImageBufferSurface(logicalSize));
+            }
+            setSourceImage(ImageBuffer::create(surface.release()));
+        }
         m_graphicsBufferAttached = true;
     }
 }