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

cc/CCRendererGL.h

 // Copyright 2010 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 CCRendererGL_h
 #define CCRendererGL_h
 
 #if USE(ACCELERATED_COMPOSITING)
 
@@ skipping 25 matching lines @@
 class CCRendererGL : public CCDirectRenderer,
                      public WebKit::WebGraphicsContext3D::WebGraphicsSwapBuffersCompleteCallbackCHROMIUM,
                      public WebKit::WebGraphicsContext3D::WebGraphicsMemoryAllocationChangedCallbackCHROMIUM ,
                      public WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback {
     WTF_MAKE_NONCOPYABLE(CCRendererGL);
 public:
     static PassOwnPtr<CCRendererGL> create(CCRendererClient*, CCResourceProvider*);
 
     virtual ~CCRendererGL();
 
-    virtual const RendererCapabilities& capabilities() const OVERRIDE { return m_capabilities; }
+    virtual const RendererCapabilities& capabilities() const OVERRIDE;
 
     WebKit::WebGraphicsContext3D* context();
 
     virtual void viewportChanged() OVERRIDE;
 
     const FloatQuad& sharedGeometryQuad() const { return m_sharedGeometryQuad; }
 
     // waits for rendering to finish
     virtual void finish() OVERRIDE;
 
@@ skipping 171 matching lines @@
 #else
 #define GLC(context, x) (x)
 #endif
 
 
 }
 
 #endif // USE(ACCELERATED_COMPOSITING)
 
 #endif