Fix CC*Renderer and CC*LayerImpl to compile with Clang

cc/CCVideoLayerImpl.h

 // Copyright 2012 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 CCVideoLayerImpl_h
 #define CCVideoLayerImpl_h
 
 #include "CCLayerImpl.h"
 #include "GraphicsContext3D.h"
 #include "IntSize.h"
@@ skipping 44 matching lines @@
         FramePlane() : resourceId(0) { }
 
         bool allocateData(CCResourceProvider*);
         void freeData(CCResourceProvider*);
     };
 
 private:
     CCVideoLayerImpl(int, WebKit::WebVideoFrameProvider*);
 
     static IntSize computeVisibleSize(const WebKit::WebVideoFrame&, unsigned plane);
-    virtual const char* layerTypeAsString() const OVERRIDE { return "VideoLayer"; }
+    virtual const char* layerTypeAsString() const OVERRIDE;
 
     void willDrawInternal(CCResourceProvider*);
     bool allocatePlaneData(CCResourceProvider*);
     bool copyPlaneData(CCResourceProvider*);
     void freePlaneData(CCResourceProvider*);
     void freeUnusedPlaneData(CCResourceProvider*);
 
     // Guards the destruction of m_provider and the frame that it provides
     Mutex m_providerMutex;
     WebKit::WebVideoFrameProvider* m_provider;
 
     WebKit::WebTransformationMatrix m_streamTextureMatrix;
 
     WebKit::WebVideoFrame* m_frame;
     GC3Denum m_format;
     CCResourceProvider::ResourceId m_externalTextureResource;
 
     // Each index in this array corresponds to a plane in WebKit::WebVideoFrame.
     FramePlane m_framePlanes[WebKit::WebVideoFrame::maxPlanes];
 };
 
 }
 
 #endif // CCVideoLayerImpl_h