[WIP] bindings: Introduce PropertyBag

Source/core/animation/AnimationTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/animation/Animation.h"
 
 #include "bindings/core/v8/Dictionary.h"
 #include "bindings/core/v8/Nullable.h"
 #include "core/animation/AnimationClock.h"
@@ skipping 61 matching lines @@
     setV8ObjectPropertyAsString(keyframe1, "offset", "0");
     setV8ObjectPropertyAsString(keyframe1, "easing", "ease-in-out");
     setV8ObjectPropertyAsString(keyframe2, "width", "0px");
     setV8ObjectPropertyAsString(keyframe2, "offset", "1");
     setV8ObjectPropertyAsString(keyframe2, "easing", "cubic-bezier(1, 1, 0.3, 0.3)");
 
     jsKeyframes.append(Dictionary(keyframe1, m_isolate));
     jsKeyframes.append(Dictionary(keyframe2, m_isolate));
 
     String value1;
-    ASSERT_TRUE(DictionaryHelper::get(jsKeyframes[0], "width", value1));
+    ASSERT_TRUE(jsKeyframes[0].get("width", value1));
     ASSERT_EQ("100px", value1);
 
     String value2;
-    ASSERT_TRUE(DictionaryHelper::get(jsKeyframes[1], "width", value2));
+    ASSERT_TRUE(jsKeyframes[1].get("width", value2));
     ASSERT_EQ("0px", value2);
 
     RefPtrWillBeRawPtr<Animation> animation = createAnimation(element.get(), jsKeyframes, 0, exceptionState);
 
     Element* target = animation->target();
     EXPECT_EQ(*element.get(), *target);
 
     const KeyframeVector keyframes = toKeyframeEffectModelBase(animation->effect())->getFrames();
 
     EXPECT_EQ(0, keyframes[0]->offset());
@@ skipping 353 matching lines @@
     EXPECT_EQ(element.get(), animation->target());
     document.timeline().play(animation.get());
     pageHolder.clear();
     element.clear();
 #if !ENABLE(OILPAN)
     EXPECT_EQ(0, animation->target());
 #endif
 }
 
 } // namespace blink