Implement WEBGL_shared_resources

Source/core/html/canvas/WebGLContextAttributes.h

Index: Source/core/html/canvas/WebGLContextAttributes.h
diff --git a/Source/core/html/canvas/WebGLContextAttributes.h b/Source/core/html/canvas/WebGLContextAttributes.h
index d609920e0773689b961d761465cc55f3a1f712fd..eedefceaeb1d4232868c8fda87e946e007c2b97e 100644
--- a/Source/core/html/canvas/WebGLContextAttributes.h
+++ b/Source/core/html/canvas/WebGLContextAttributes.h
@@ -34,6 +34,8 @@
 
 namespace WebCore {
 
+class WebGLShareGroup;
+
 class WebGLContextAttributes : public CanvasContextAttributes, public ScriptWrappable {
 public:
     virtual ~WebGLContextAttributes();
@@ -71,6 +73,10 @@ public:
     bool preserveDrawingBuffer() const;
     void setPreserveDrawingBuffer(bool);
 
+    // Which share group this context uses.
+    PassRefPtr<WebGLShareGroup> group() const;
+    void setGroup(PassRefPtr<WebGLShareGroup>);
+
     // Fetches a copy of the attributes stored in this object in a
     // form that can be used to initialize a GraphicsContext3D.
     GraphicsContext3D::Attributes attributes() const;
@@ -81,6 +87,7 @@ protected:
 
 private:
     GraphicsContext3D::Attributes m_attrs;
+    RefPtr<WebGLShareGroup> m_shareGroup;
 };
 
 } // namespace WebCore