Implement cross-origin attributes using access check interceptors.

third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp

Index: third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp b/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
index edada54b4d3a554001d01677200f49bb29245970..622c5255e6ac5a472a7f8509e00a7bb16d091bf9 100644
--- a/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
@@ -115,8 +115,12 @@ void WindowProxy::disposeContext(GlobalDetachmentBehavior behavior) {
 
   m_document.clear();
 
-  if (behavior == DetachGlobal)
+  if (behavior == DetachGlobal) {
+    // Clean up state on the global proxy, which will be reused.
+    // TODO(dcheng): Check if this is needed.

[dcheng, 2016/11/02 01:46:42]

We only detach globals on navigation, so the internal fields will be overwritten
shortly after this anyway.

That being said, it seems nice to do this on a conceptual basis.

[haraken, 2016/11/02 04:30:32]

Makes sense. Let's make the change in a separate CL.

[dcheng, 2016/11/02 07:45:32]

It kind of makes sense in this CL though? Previously, we weren't setting these
fields or using them: now that we are, I think we should clean them up?

[Yuki, 2016/11/02 08:26:39]

I vote to keep |clearNativeInfo| here.  Just my preference.

+    V8DOMWrapper::clearNativeInfo(m_isolate, context->Global());
     m_scriptState->detachGlobalObject();
+  }
 
   m_scriptState->disposePerContextData();
 
@@ -366,6 +370,11 @@ bool WindowProxy::setupWindowPrototypeChain() {
   v8::Local<v8::Context> context = m_scriptState->context();
   // The global proxy object.  Note this is not the global object.
   v8::Local<v8::Object> globalProxy = context->Global();
+  V8DOMWrapper::setNativeInfo(m_isolate, globalProxy, wrapperTypeInfo, window);
+  // Mark the handle to be traced by Oilpan, since the global proxy has a
+  // reference to the DOMWindow.
+  DCHECK(m_globalProxy == globalProxy);
+  m_globalProxy.get().SetWrapperClassId(wrapperTypeInfo->wrapperClassId);

[haraken, 2016/11/02 04:30:32]

Can we call V8DOMWrapper::associateObjectWithWrapper instead of calling
setNativeInfo and etWrapperClassId?

[dcheng, 2016/11/02 07:45:32]

My concern with this is associateObjectWithWrapper doesn't have any way to
unassociate, so subsequent calls will not work correctly.

Perhaps a followup?

   // The global object, aka window wrapper object.
   v8::Local<v8::Object> windowWrapper =
       globalProxy->GetPrototype().As<v8::Object>();