Extract a DOMWindow interface from LocalDOMWindow and use it in the idl.

Source/bindings/core/v8/custom/V8InjectedScriptManager.cpp

Index: Source/bindings/core/v8/custom/V8InjectedScriptManager.cpp
diff --git a/Source/bindings/core/v8/custom/V8InjectedScriptManager.cpp b/Source/bindings/core/v8/custom/V8InjectedScriptManager.cpp
index 184136eaa2329cd4ea4b93bf35b4a2aa4448af6f..073dbd7fc954e2ae334b9564ad11bac36a02de8d 100644
--- a/Source/bindings/core/v8/custom/V8InjectedScriptManager.cpp
+++ b/Source/bindings/core/v8/custom/V8InjectedScriptManager.cpp
@@ -118,7 +118,7 @@ bool InjectedScriptManager::canAccessInspectedWindow(ScriptState* scriptState)
     v8::Handle<v8::Object> holder = V8Window::findInstanceInPrototypeChain(global, scriptState->isolate());
     if (holder.IsEmpty())
         return false;
-    LocalFrame* frame = V8Window::toImpl(holder)->frame();
+    LocalFrame* frame = toLocalDOMWindow(V8Window::toImpl(holder))->frame();

[dcheng, 2014/10/31 03:20:40]

For things like this, I assume that the browser will always route these requests
to the renderer hosting the frame. However, much of this browser-side routing
does not exist today, so I expect that we'll hit a bunch of asserts in
--site-per-process mode.

[haraken, 2014/10/31 06:07:04]

Don't we need to have:

  LocalDOMWindow* window = toLocalDOMWindow(V8Window::toImpl(holder));
  if (!window)
    return false;
  LocalFrame* frame = window->frame();

?

[dcheng, 2014/10/31 06:31:01]

The browser should be routing any calls of this nature correctly so we never end
up in the "wrong renderer": in other words, this should only be called in a
renderer where the frame is a LocalFrame. toLocalDOMWindow() will actually
RELEASE_ASSERT if the DOMWindow is of the wrong type. It's almost guaranteed
that this will assert right now. However, it only affects --site-per-process so
I'd prefer to make this as aggressive as possible so we can find problematic
areas. In the final state, there should be no checks for
isLocalDOMWindow()--since the browser will always route it to the renderer
hosting the frame, the DOMWindow will always be local.

 
     return BindingSecurity::shouldAllowAccessToFrame(scriptState->isolate(), frame, DoNotReportSecurityError);
 }