Update from https://crrev.com/308996

cc/output/renderer_pixeltest.cc

Index: cc/output/renderer_pixeltest.cc
diff --git a/cc/output/renderer_pixeltest.cc b/cc/output/renderer_pixeltest.cc
index 58205a91869e87e60a68e70659bc898e23549251..c7582fe2a78cf26abf8c165e4a42c51d8b3daf7e 100644
--- a/cc/output/renderer_pixeltest.cc
+++ b/cc/output/renderer_pixeltest.cc
@@ -167,8 +167,8 @@ class FuzzyForSoftwareOnlyPixelComparator : public PixelComparator {
   explicit FuzzyForSoftwareOnlyPixelComparator(bool discard_alpha)
       : fuzzy_(discard_alpha), exact_(discard_alpha) {}
 
-  virtual bool Compare(const SkBitmap& actual_bmp,
-                       const SkBitmap& expected_bmp) const;
+  bool Compare(const SkBitmap& actual_bmp,
+               const SkBitmap& expected_bmp) const override;
 
  private:
   FuzzyPixelOffByOneComparator fuzzy_;