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

cc/CCLayerTreeHostCommon.h

 // Copyright 2011 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 CCLayerTreeHostCommon_h
 #define CCLayerTreeHostCommon_h
 
 #include "IntRect.h"
 #include "IntSize.h"
 #include <public/WebTransformationMatrix.h>
@@ skipping 25 matching lines @@
     // from the given root layer (including mask and replica layers).
     template<typename LayerType> static LayerType* findLayerInSubtree(LayerType* rootLayer, int layerId);
 
     struct ScrollUpdateInfo {
         int layerId;
         IntSize scrollDelta;
     };
 };
 
 struct CCScrollAndScaleSet {
+    CCScrollAndScaleSet();
+    ~CCScrollAndScaleSet();
+
     Vector<CCLayerTreeHostCommon::ScrollUpdateInfo> scrolls;
     float pageScaleDelta;
 };
 
 template<typename LayerType>
 bool CCLayerTreeHostCommon::renderSurfaceContributesToTarget(LayerType* layer, int targetSurfaceLayerID)
 {
     // A layer will either contribute its own content, or its render surface's content, to
     // the target surface. The layer contributes its surface's content when both the
     // following are true:
@@ skipping 20 matching lines @@
     for (size_t i = 0; i < rootLayer->children().size(); ++i) {
         if (LayerType* found = findLayerInSubtree(rootLayer->children()[i].get(), layerId))
             return found;
     }
     return 0;
 }
 
 } // namespace cc
 
 #endif