Switch HTMLCanvasElement over to new-style ExceptionState.

Source/bindings/v8/custom/V8HTMLCanvasElementCustom.cpp

 /*
  * Copyright (C) 2007-2009 Google Inc. All rights reserved.
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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 116 matching lines @@
         return;
     }
     ASSERT_NOT_REACHED();
     v8SetReturnValueNull(info);
 }
 
 void V8HTMLCanvasElement::toDataURLMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Handle<v8::Object> holder = info.Holder();
     HTMLCanvasElement* canvas = V8HTMLCanvasElement::toNative(holder);
-    ExceptionState exceptionState(info.Holder(), info.GetIsolate());
+    ExceptionState exceptionState(ExceptionState::ExecutionContext, "toDataURL", "HTMLCanvasElement", info.Holder(), info.GetIsolate());
 
     V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, type, info[0]);
     double quality;
     double* qualityPtr = 0;
     if (info.Length() > 1 && info[1]->IsNumber()) {
         quality = info[1]->NumberValue();
         qualityPtr = &quality;
     }
 
     String result = canvas->toDataURL(type, qualityPtr, exceptionState);
     exceptionState.throwIfNeeded();
     v8SetReturnValueStringOrUndefined(info, result, info.GetIsolate());
 }
 
 } // namespace WebCore