Fix virtual/override/final usage in Source/platform/.

Source/platform/graphics/paint/FloatClipDisplayItem.h

 // 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.
 
 #ifndef FloatClipDisplayItem_h
 #define FloatClipDisplayItem_h
 
 #include "platform/PlatformExport.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/graphics/paint/DisplayItem.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace blink {
 
 class RoundedRect;
 
 class PLATFORM_EXPORT FloatClipDisplayItem : public PairedBeginDisplayItem {
 public:
     FloatClipDisplayItem(const DisplayItemClientWrapper& client, Type type, const FloatRect& clipRect)
         : PairedBeginDisplayItem(client, type)
         , m_clipRect(clipRect)
     {
         ASSERT(isFloatClipType(type));
     }
 
-    virtual void replay(GraphicsContext&) override;
-    virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    void replay(GraphicsContext&) override;
+    void appendToWebDisplayItemList(WebDisplayItemList*) const override;
 
 private:
 #ifndef NDEBUG
-    virtual void dumpPropertiesAsDebugString(WTF::StringBuilder&) const override;
+    void dumpPropertiesAsDebugString(WTF::StringBuilder&) const override;
 #endif
 
     const FloatRect m_clipRect;
 };
 
 class PLATFORM_EXPORT EndFloatClipDisplayItem : public PairedEndDisplayItem {
 public:
     EndFloatClipDisplayItem(const DisplayItemClientWrapper& client, Type type)
         : PairedEndDisplayItem(client, type)
     {
         ASSERT(isEndFloatClipType(type));
     }
 
-    virtual void replay(GraphicsContext&) override;
-    virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    void replay(GraphicsContext&) override;
+    void appendToWebDisplayItemList(WebDisplayItemList*) const override;
 
 private:
 #if ENABLE(ASSERT)
-    virtual bool isEndAndPairedWith(DisplayItem::Type otherType) const override final { return DisplayItem::isFloatClipType(otherType); }
+    bool isEndAndPairedWith(DisplayItem::Type otherType) const final { return DisplayItem::isFloatClipType(otherType); }
 #endif
 };
 
 } // namespace blink
 
 #endif // FloatClipDisplayItem_h