Avoid caching resources for volatile bitmap shaders

src/core/SkBitmapProvider.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapProvider.h"
 #include "SkImage_Base.h"
 #include "SkPixelRef.h"
@@ skipping 31 matching lines @@
 SkImageInfo SkBitmapProvider::info() const {
     if (fImage) {
         return as_IB(fImage)->onImageInfo();
     } else {
         return fBitmap.info();
     }
 }
 
 bool SkBitmapProvider::isVolatile() const {
     if (fImage) {
-        return false;   // add flag to images?
+        // add flag to images?
+        const SkBitmap* bm = as_IB(fImage)->onPeekBitmap();
+        return bm ? bm->isVolatile() : false;
     } else {
         return fBitmap.isVolatile();
     }
 }
 
 SkBitmapCacheDesc SkBitmapProvider::makeCacheDesc(int w, int h) const {
     return fImage ? SkBitmapCacheDesc::Make(fImage, w, h) : SkBitmapCacheDesc::Make(fBitmap, w, h);
 }
 
 SkBitmapCacheDesc SkBitmapProvider::makeCacheDesc() const {
     return fImage ? SkBitmapCacheDesc::Make(fImage) : SkBitmapCacheDesc::Make(fBitmap);
 }
 
 void SkBitmapProvider::notifyAddedToCache() const {
     if (fImage) {
         as_IB(fImage)->notifyAddedToCache();
     } else {
         fBitmap.pixelRef()->notifyAddedToCache();
     }
 }
 
 bool SkBitmapProvider::asBitmap(SkBitmap* bm) const {
     if (fImage) {
         return as_IB(fImage)->getROPixels(bm, SkImage::kAllow_CachingHint);
     } else {
         *bm = fBitmap;
         return true;
     }
 }