Remove the MSAA WebSetting, which is not read or used.

third_party/WebKit/Source/core/page/Page.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 182 matching lines @@
     bool isPageVisible() const;
 
     bool isCursorVisible() const;
     void setIsCursorVisible(bool isVisible) { m_isCursorVisible = isVisible; }
 
 #if ENABLE(ASSERT)
     void setIsPainting(bool painting) { m_isPainting = painting; }
     bool isPainting() const { return m_isPainting; }
 #endif
 
-    class CORE_EXPORT MultisamplingChangedObserver : public GarbageCollectedMixin {
-    public:
-        virtual void multisamplingChanged(bool) = 0;
-    };
-
-    void addMultisamplingChangedObserver(MultisamplingChangedObserver*);
-#if !ENABLE(OILPAN)
-    void removeMultisamplingChangedObserver(MultisamplingChangedObserver*);
-#endif
-
     void didCommitLoad(LocalFrame*);
 
     void acceptLanguagesChanged();
 
     static void networkStateChanged(bool online);
 
     MemoryPurgeController& memoryPurgeController();
 
     void purgeMemory(DeviceKind) override;
 
@@ skipping 57 matching lines @@
     float m_deviceScaleFactor;
 
     PageVisibilityState m_visibilityState;
 
     bool m_isCursorVisible;
 
 #if ENABLE(ASSERT)
     bool m_isPainting;
 #endif
 
-    HeapHashSet<WeakMember<MultisamplingChangedObserver>> m_multisamplingChangedObservers;
-
     // A pointer to all the interfaces provided to in-process Frames for this Page.
     // FIXME: Most of the members of Page should move onto FrameHost.
     Member<FrameHost> m_frameHost;
 
     Member<MemoryPurgeController> m_memoryPurgeController;
 
     Timer<Page> m_timerForCompressStrings;
 };
 
 extern template class CORE_EXTERN_TEMPLATE_EXPORT Supplement<Page>;
 
 } // namespace blink
 
 #endif // Page_h