comment out getBufferSubDataAsync so conformance2/context/methods-2.html can pass

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.idl

Index: third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.idl
diff --git a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.idl b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.idl
index 8598ade1ad962d722f9fc6e5283d2edeb5c4dc7c..b82610dd54d19b3d364be8c65230f2f885671610 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.idl
+++ b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.idl
@@ -282,7 +282,8 @@ typedef unsigned long long GLuint64;
     void bufferSubData(GLenum target, GLintptr dstByteOffset, ArrayBufferView srcData, GLuint srcOffset, optional GLuint length = 0);
     void copyBufferSubData(GLenum readTarget, GLenum writeTarget, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
     void getBufferSubData(GLenum target, GLintptr srcByteOffset, ArrayBufferView dstData, optional GLuint dstOffset = 0, optional GLuint length = 0);
-    [CallWith=ScriptState, RuntimeEnabled=ExperimentalCanvasFeatures] Promise<ArrayBufferView> getBufferSubDataAsync(GLenum target, GLintptr srcByteOffset, ArrayBufferView dstData, optional GLuint dstOffset = 0, optional GLuint length = 0);
+    // TODO(kainino): Move getBufferSubDataAsync to an extension. http://crbug.com/616554
+    //[CallWith=ScriptState, RuntimeEnabled=ExperimentalCanvasFeatures] Promise<ArrayBufferView> getBufferSubDataAsync(GLenum target, GLintptr srcByteOffset, ArrayBufferView dstData, optional GLuint dstOffset = 0, optional GLuint length = 0);
 
     /* Framebuffer objects */
     void blitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter);