Fix up all the easy virtual ... SK_OVERRIDE cases.

tools/skpdiff/SkDifferentPixelsMetric.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDifferentPixelsMetric_DEFINED
 #define SkDifferentPixelsMetric_DEFINED
 
 #include "SkTDArray.h"
 
 #if SK_SUPPORT_OPENCL
 #include "SkCLImageDiffer.h"
 #else
 #include "SkImageDiffer.h"
 #endif
 
 /**
  * A differ that measures the percentage of different corresponding pixels. If the two images are
  * not the same size or have no pixels, the result will always be zero.
  */
 class SkDifferentPixelsMetric :
 #if SK_SUPPORT_OPENCL
     public SkCLImageDiffer {
 #else
     public SkImageDiffer {
 #endif
 public:
-    virtual const char* getName() const SK_OVERRIDE;
+    const char* getName() const SK_OVERRIDE;
     virtual bool diff(SkBitmap* baseline, SkBitmap* test,
                       const BitmapsToCreate& bitmapsToCreate,
                       Result* result) const SK_OVERRIDE;
 
 protected:
 #if SK_SUPPORT_OPENCL
-    virtual bool onInit() SK_OVERRIDE;
+    bool onInit() SK_OVERRIDE;
 #endif
 
 private:
 #if SK_SUPPORT_OPENCL
     cl_kernel fKernel;
 
     typedef SkCLImageDiffer INHERITED;
 #else
     typedef SkImageDiffer INHERITED;
 #endif
 };
 
 #endif