This CL implements the first draft of Canvas 2D Context Attributes, aka getContext('2d', { alpha: f…

Source/core/platform/graphics/ImageBuffer.h

Index: Source/core/platform/graphics/ImageBuffer.h
diff --git a/Source/core/platform/graphics/ImageBuffer.h b/Source/core/platform/graphics/ImageBuffer.h
index cda6678fad18ba1dd0efe105b382a4d36e199e5e..3d97575fd2523921c845902089780f40f7a4b4dd 100644
--- a/Source/core/platform/graphics/ImageBuffer.h
+++ b/Source/core/platform/graphics/ImageBuffer.h
@@ -73,14 +73,19 @@ namespace WebCore {
         Unscaled
     };
 
+    enum OpacityMode {
+        NonOpaque,
+        Opaque,
+    };
+
     class ImageBuffer {
         WTF_MAKE_NONCOPYABLE(ImageBuffer); WTF_MAKE_FAST_ALLOCATED;
     public:
         // Will return a null pointer on allocation failure.
-        static PassOwnPtr<ImageBuffer> create(const IntSize& size, float resolutionScale = 1, ColorSpace colorSpace = ColorSpaceDeviceRGB, RenderingMode renderingMode = Unaccelerated)
+        static PassOwnPtr<ImageBuffer> create(const IntSize& size, float resolutionScale = 1, ColorSpace colorSpace = ColorSpaceDeviceRGB, RenderingMode renderingMode = Unaccelerated, OpacityMode opacityMode = NonOpaque)
         {
             bool success = false;
-            OwnPtr<ImageBuffer> buf = adoptPtr(new ImageBuffer(size, resolutionScale, colorSpace, renderingMode, success));
+            OwnPtr<ImageBuffer> buf = adoptPtr(new ImageBuffer(size, resolutionScale, colorSpace, renderingMode, opacityMode, success));
             if (!success)
                 return nullptr;
             return buf.release();
@@ -144,7 +149,7 @@ namespace WebCore {
 
         // This constructor will place its success into the given out-variable
         // so that create() knows when it should return failure.
-        ImageBuffer(const IntSize&, float resolutionScale, ColorSpace, RenderingMode, bool& success);
+        ImageBuffer(const IntSize&, float resolutionScale, ColorSpace, RenderingMode, OpacityMode, bool& success);
         ImageBuffer(const IntSize&, float resolutionScale, ColorSpace, const GraphicsContext*, bool hasAlpha, bool& success);
     };