Have Node::document() return a reference instead of a pointer

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 76 matching lines @@
         }
         attributes = canvas2DAttributes;
     }
     CanvasRenderingContext* result = imp->getContext(contextId, attributes.get());
     if (!result) {
         v8SetReturnValueNull(args);
         return;
     }
     if (result->is2d()) {
         v8::Handle<v8::Value> v8Result = toV8(static_cast<CanvasRenderingContext2D*>(result), args.Holder(), args.GetIsolate());
-        if (InspectorInstrumentation::canvasAgentEnabled(imp->document())) {
+        if (InspectorInstrumentation::canvasAgentEnabled(&imp->document())) {
             ScriptState* scriptState = ScriptState::forContext(v8::Context::GetCurrent());
             ScriptObject context(scriptState, v8::Handle<v8::Object>::Cast(v8Result));
-            ScriptObject wrapped = InspectorInstrumentation::wrapCanvas2DRenderingContextForInstrumentation(imp->document(), context);
+            ScriptObject wrapped = InspectorInstrumentation::wrapCanvas2DRenderingContextForInstrumentation(&imp->document(), context);
             if (!wrapped.hasNoValue()) {
                 v8SetReturnValue(args, wrapped.v8Value());
                 return;
             }
         }
         v8SetReturnValue(args, v8Result);
         return;
     }
     if (result->is3d()) {
         v8::Handle<v8::Value> v8Result = toV8(static_cast<WebGLRenderingContext*>(result), args.Holder(), args.GetIsolate());
-        if (InspectorInstrumentation::canvasAgentEnabled(imp->document())) {
+        if (InspectorInstrumentation::canvasAgentEnabled(&imp->document())) {
             ScriptState* scriptState = ScriptState::forContext(v8::Context::GetCurrent());
             ScriptObject glContext(scriptState, v8::Handle<v8::Object>::Cast(v8Result));
-            ScriptObject wrapped = InspectorInstrumentation::wrapWebGLRenderingContextForInstrumentation(imp->document(), glContext);
+            ScriptObject wrapped = InspectorInstrumentation::wrapWebGLRenderingContextForInstrumentation(&imp->document(), glContext);
             if (!wrapped.hasNoValue()) {
                 v8SetReturnValue(args, wrapped.v8Value());
                 return;
             }
         }
         v8SetReturnValue(args, v8Result);
         return;
     }
     ASSERT_NOT_REACHED();
     v8SetReturnValueNull(args);
@@ skipping 12 matching lines @@
         quality = args[1]->NumberValue();
         qualityPtr = &quality;
     }
 
     String result = canvas->toDataURL(type, qualityPtr, es);
     es.throwIfNeeded();
     v8SetReturnValueStringOrUndefined(args, result, args.GetIsolate());
 }
 
 } // namespace WebCore