[Oilpan] Migrate classes under module/webgl onto oilpan heap

Source/modules/webgl/WebGLContextGroup.h

Index: Source/modules/webgl/WebGLContextGroup.h
diff --git a/Source/modules/webgl/WebGLContextGroup.h b/Source/modules/webgl/WebGLContextGroup.h
index e5e6c8cd5e1d93a0f3eb77c9eaf1c852af05a925..3a89bf4f563826062ffb45ddde6e95546a436273 100644
--- a/Source/modules/webgl/WebGLContextGroup.h
+++ b/Source/modules/webgl/WebGLContextGroup.h
@@ -71,7 +71,7 @@ private:
     // WebGLContextGroup takes care of detaching the group objects if
     // the set of WebGLRenderingContextBase contexts becomes empty.
     HashSet<WebGLRenderingContextBase*> m_contexts;
-    HashSet<WebGLSharedObject*> m_groupObjects;
+    PersistentHeapHashSet<Member<WebGLSharedObject>> m_groupObjects;

[Ken Russell (switch to Gerrit), 2015/08/01 00:11:56]

I think we should file a bug about removing these m_groupObjects, similarly to
comment in WebGLRenderingContextBase about removing m_contextObjects. I think
that with sufficient modeling of the OpenGL state so that live WebGLObjects
don't get accidentally GC'd, we ought to be able to avoid these weak references
from the WebGLRenderingContextBase to the objects it's allocated. Do you agree?

[peria, 2015/08/03 09:00:35]

I agree to remove them, but I think it is not good to make those reference map
strong references.
I changed m_groupObjects a weak reference map.

 };
 
 } // namespace blink