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

gm/imagefiltersgraph.cpp

Index: gm/imagefiltersgraph.cpp
diff --git a/gm/imagefiltersgraph.cpp b/gm/imagefiltersgraph.cpp
index ae6f4a6d1fa809a510a6afceea2b8c70d7a985ee..c66ee83ccfc96b7a8a752151dd1c8b1ccfa8793f 100644
--- a/gm/imagefiltersgraph.cpp
+++ b/gm/imagefiltersgraph.cpp
@@ -66,7 +66,7 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SimpleOffsetFilter);
 
 protected:
-    virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE {
+    void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.writeScalar(fDX);
         buffer.writeScalar(fDY);
@@ -102,7 +102,7 @@ public:
     ImageFiltersGraphGM() {}
 
 protected:
-    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+    uint32_t onGetFlags() const SK_OVERRIDE {
         return kSkipTiled_Flag;
     }