Added infrastructure for optimizing new CanvasArray types in WebGL...

src/handles.cc

Index: src/handles.cc
===================================================================
--- src/handles.cc	(revision 3095)
+++ src/handles.cc	(working copy)
@@ -345,7 +345,7 @@
 Handle<Object> SetElement(Handle<JSObject> object,
                           uint32_t index,
                           Handle<Object> value) {
-  if (object->HasPixelElements()) {
+  if (object->HasPixelElements() || object->HasExternalArrayElements()) {
     if (!value->IsSmi() && !value->IsHeapNumber() && !value->IsUndefined()) {
       bool has_exception;
       Handle<Object> number = Execution::ToNumber(value, &has_exception);