bindings: Use BooleanValue(v8::Context) in V8ErrorHandler

Source/bindings/core/v8/V8ErrorHandler.cpp

 /*
  * Copyright (C) 2010 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 71 matching lines @@
 {
     v8::Local<v8::Value> wrappedEvent = toV8(event, creationContext, isolate);
     if (!wrappedEvent.IsEmpty()) {
         ASSERT(wrappedEvent->IsObject());
         V8HiddenValue::setHiddenValue(isolate, v8::Local<v8::Object>::Cast(wrappedEvent), V8HiddenValue::error(isolate), data);
     }
 }
 
 bool V8ErrorHandler::shouldPreventDefault(v8::Local<v8::Value> returnValue)
 {
-    return returnValue->IsBoolean() && returnValue->BooleanValue();
+    return returnValue->IsBoolean() && returnValue->BooleanValue(isolate()->GetCurrentContext()).FromJust();

[bashi, 2015/03/06 07:16:18]

Correct me if I'm wrong: I assume that BooleanValue is never |Nothing| when
IsBoolean() is true.

[dcarney, 2015/03/06 07:32:26]

If you know the object's type exactly, always use As or Cast instead.

 }
 
 } // namespace blink