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

include/core/SkWeakRefCnt.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkWeakRefCnt_DEFINED
 #define SkWeakRefCnt_DEFINED
 
@@ skipping 129 matching lines @@
         by the object's class.
     */
     virtual void weak_dispose() const {
     }
 
 private:
     /** Called when the strong reference count goes to zero. Calls weak_dispose
         on the object and releases the implicit weak reference held
         collectively by the strong references.
     */
-    virtual void internal_dispose() const SK_OVERRIDE {
+    void internal_dispose() const SK_OVERRIDE {
         weak_dispose();
         weak_unref();
     }
 
     /* Invariant: fWeakCnt = #weak + (fRefCnt > 0 ? 1 : 0) */
     mutable int32_t fWeakCnt;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif