scaling API on SkPixmap

src/core/SkBitmapProvider.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBitmapProvider_DEFINED
 #define SkBitmapProvider_DEFINED
 
 #include "SkBitmap.h"
 #include "SkImage.h"
 #include "SkBitmapCache.h"
 
 class SkBitmapProvider {
 public:
     explicit SkBitmapProvider(const SkBitmap& bm) : fBitmap(bm) {}
     explicit SkBitmapProvider(const SkImage* img) : fImage(SkSafeRef(img)) {}
     SkBitmapProvider(const SkBitmapProvider& other)
         : fBitmap(other.fBitmap)
         , fImage(SkSafeRef(other.fImage.get()))
     {}
 
     int width() const;
     int height() const;
     uint32_t getID() const;
 
     bool validForDrawing() const;
     SkImageInfo info() const;
+    bool isVolatile() const;
 
     SkBitmapCacheDesc makeCacheDesc(int w, int h) const;
     SkBitmapCacheDesc makeCacheDesc() const;
     void notifyAddedToCache() const;
 
     // Only call this if you're sure you need the bits, since it maybe expensive
     // ... cause a decode and cache, or gpu-readback
     bool asBitmap(SkBitmap*) const;
 
 private:
     SkBitmap fBitmap;
     SkAutoTUnref<const SkImage> fImage;
 };
 
 #endif