Oilpan: move 2D Canvas and WebGL objects to the heap.

Source/core/html/canvas/WebGLBuffer.cpp

Index: Source/core/html/canvas/WebGLBuffer.cpp
diff --git a/Source/core/html/canvas/WebGLBuffer.cpp b/Source/core/html/canvas/WebGLBuffer.cpp
index 8eab4d8161e5a1ccae9ce0ac56d463f3114ca161..4400d0ade85e3adf4ce1bd2e2fecf1f98926c148 100644
--- a/Source/core/html/canvas/WebGLBuffer.cpp
+++ b/Source/core/html/canvas/WebGLBuffer.cpp
@@ -31,9 +31,9 @@
 
 namespace blink {
 
-PassRefPtr<WebGLBuffer> WebGLBuffer::create(WebGLRenderingContextBase* ctx)
+PassRefPtrWillBeRawPtr<WebGLBuffer> WebGLBuffer::create(WebGLRenderingContextBase* ctx)
 {
-    return adoptRef(new WebGLBuffer(ctx));
+    return adoptRefWillBeNoop(new WebGLBuffer(ctx));
 }
 
 WebGLBuffer::WebGLBuffer(WebGLRenderingContextBase* ctx)
@@ -46,7 +46,16 @@ WebGLBuffer::WebGLBuffer(WebGLRenderingContextBase* ctx)
 
 WebGLBuffer::~WebGLBuffer()
 {
-    deleteObject(0);
+    // Delete the buffer's platform object. This object will have been
+    // detached from the WebGLContextGroup if the group object was
+    // finalized first. With Oilpan not enabled, it always will be,
+    // but with Oilpan enabled, the WebGLBuffer might end up being
+    // finalized first. In which case detachment is needed to ensure
+    // that the platform object is indeed deleted.
+    //
+    // To keep the code regular, the trivial detach()ment is always
+    // performed.
+    detachAndDeleteObject();
 }
 
 void WebGLBuffer::deleteObjectImpl(blink::WebGraphicsContext3D* context3d, Platform3DObject object)