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

tests/PixelRefTest.cpp

 #include "Test.h"
 
 #include "SkMallocPixelRef.h"
 #include "SkPixelRef.h"
 
 class TestListener : public SkPixelRef::GenIDChangeListener {
 public:
     explicit TestListener(int* ptr) : fPtr(ptr) {}
-    virtual void onChange() SK_OVERRIDE { (*fPtr)++; }
+    void onChange() SK_OVERRIDE { (*fPtr)++; }
 private:
     int* fPtr;
 };
 
 DEF_TEST(PixelRef_GenIDChange, r) {
     SkImageInfo info = SkImageInfo::MakeN32Premul(10, 10);
 
     SkAutoTUnref<SkPixelRef> pixelRef(SkMallocPixelRef::NewAllocate(info, 0, NULL));
 
     // Register a listener.
@@ skipping 17 matching lines @@
     REPORTER_ASSERT(r, 0 != pixelRef->getGenerationID());
     pixelRef->addGenIDChangeListener(SkNEW_ARGS(TestListener, (&count)));
     pixelRef->notifyPixelsChanged();
     REPORTER_ASSERT(r, 1 == count);
 
     // Quick check that NULL is safe.
     REPORTER_ASSERT(r, 0 != pixelRef->getGenerationID());
     pixelRef->addGenIDChangeListener(NULL);
     pixelRef->notifyPixelsChanged();
 }