Cleanup: Mark some overridden methods with 'SK_OVERRIDE'.

src/gpu/GrDrawTarget.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawTarget_DEFINED
 #define GrDrawTarget_DEFINED
 
@@ skipping 826 matching lines @@
     virtual void purgeResources() SK_OVERRIDE {
         // The clip mask manager can rebuild all its clip masks so just
         // get rid of them all.
         fClipMaskManager.purgeResources();
     };
 
 protected:
     GrClipMaskManager           fClipMaskManager;
 
 private:
-    GrClipMaskManager* clipMaskManager() { return &fClipMaskManager; }
+    GrClipMaskManager* clipMaskManager() SK_OVERRIDE { return &fClipMaskManager; }
 
     virtual bool setupClip(const SkRect* devBounds,
                            GrDrawState::AutoRestoreEffects* are,
                            GrDrawState::AutoRestoreStencil* ars,
                            GrDrawState*,
                            GrClipMaskManager::ScissorState* scissorState) SK_OVERRIDE;
 
     typedef GrDrawTarget INHERITED;
 };
 
 #endif