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

gm/gradient_matrix.cpp

Index: gm/gradient_matrix.cpp
diff --git a/gm/gradient_matrix.cpp b/gm/gradient_matrix.cpp
index 275acc88684cd22e3dd30750e33b8e61a97007e8..94f40cba864708073d913221b5709bf45e56cef4 100644
--- a/gm/gradient_matrix.cpp
+++ b/gm/gradient_matrix.cpp
@@ -120,7 +120,7 @@ public:
     }
 
 protected:
-    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+    uint32_t onGetFlags() const SK_OVERRIDE {
         return kSkipTiled_Flag;
     }
 
@@ -128,11 +128,11 @@ protected:
         return SkString("gradient_matrix");
     }
 
-    virtual SkISize onISize() SK_OVERRIDE {
+    SkISize onISize() SK_OVERRIDE {
         return SkISize::Make(800, 800);
     }
 
-    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+    void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         draw_gradients(canvas, &make_linear_gradient,
                       linearPts, SK_ARRAY_COUNT(linearPts));