Support ImageData cloning in the V8-based structured clone path.

third_party/WebKit/Source/bindings/core/v8/ExceptionState.h

 /*
  * Copyright (C) 2013 Google 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 109 matching lines @@
         DCHECK(!m_exception.isEmpty());
         return m_exception.newLocal(m_isolate);
     }
 
     // This method clears out the exception which |this| has.
     ScriptPromise reject(ScriptState*);
 
     // This method clears out the exception which |this| has.
     void reject(ScriptPromiseResolver*);
 
+    ContextType context() const { return m_context; }
     const char* propertyName() const { return m_propertyName; }
     const char* interfaceName() const { return m_interfaceName; }
 
     String addExceptionContext(const String&) const;
 
 protected:
     // An ExceptionCode for the case that an exception is rethrown.  In that
     // case, we cannot determine an exception code.
     static const int kRethrownException = UnknownError;
 
@@ skipping 42 matching lines @@
     void throwDOMException(const ExceptionCode&, const String& message) override;
     void throwTypeError(const String& message) override;
     void throwSecurityError(const String& sanitizedMessage, const String& unsanitizedMessage) override;
     void throwRangeError(const String& message) override;
     void rethrowV8Exception(v8::Local<v8::Value>) override;
 };
 
 } // namespace blink
 
 #endif // ExceptionState_h