Special-case LocalDOMWindow for same-origin access in bindings.

third_party/WebKit/Source/core/timing/Performance.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 61 matching lines @@
 
  private:
   explicit Performance(LocalFrame*);
 
   // ContextLifecycleObserver overrides.
   void contextDestroyed(ExecutionContext*) override;
 
   static std::pair<String, DOMWindow*> sanitizedAttribution(
       ExecutionContext*,
       bool hasMultipleContexts,
-      Frame* observerFrame);
+      LocalFrame* observerFrame);

[dcheng, 2017/02/01 07:22:59]

We can change this because if you read the long task timing code, it's always
passing in Performance::frame(), which by definition is local.

 
   // PerformanceMonitor::Client implementation.
   void reportLongTask(double startTime,
                       double endTime,
                       ExecutionContext* taskContext,
                       bool hasMultipleContexts) override;
 
   mutable Member<PerformanceNavigation> m_navigation;
   mutable Member<PerformanceTiming> m_timing;
 };
 
 }  // namespace blink
 
 #endif  // Performance_h