Fix cpplint errors in cc/(animation|input|layers|trees|test)/

cc/layers/video_frame_provider.h

Index: cc/layers/video_frame_provider.h
diff --git a/cc/layers/video_frame_provider.h b/cc/layers/video_frame_provider.h
index d59dbe2cad01a813d0d206ef216c3cb601a460ce..784d951fe52fcef7e8476b96bd910cc00b82f61f 100644
--- a/cc/layers/video_frame_provider.h
+++ b/cc/layers/video_frame_provider.h
@@ -35,6 +35,9 @@ class VideoFrameProvider {
 
     // Notifies the provider's client of a new UV transform matrix to be used.
     virtual void DidUpdateMatrix(const float* matrix) = 0;
+
+   protected:
+    virtual ~Client() {}
   };
 
   // May be called from any thread, but there must be some external guarantee