Add SkPurgeGlobalDiscardableMemoryPool, needed to replace SkImageRef

include/core/SkImageGenerator.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageGenerator_DEFINED
 #define SkImageGenerator_DEFINED
 
@@ skipping 16 matching lines @@
  *  SkDELETE() on the generator.  Therefore, generator should be
  *  allocated with SkNEW() or SkNEW_ARGS().
  *
  *  @param destination Upon success, this bitmap will be
  *  configured and have a pixelref installed.
  *
  *  @return true iff successful.
  */
 SK_API bool SkInstallDiscardablePixelRef(SkImageGenerator*, SkBitmap* destination);
 
+/**
+ *  Purges all unlocked discardable memory in Skia's global
+ *  discardable memory pool.
+ */
+SK_API void SkPurgeGlobalDiscardableMemoryPool();
+
 
 /**
  *  An interface that allows a purgeable PixelRef (such as a
  *  SkDiscardablePixelRef) to decode and re-decode an image as needed.
  */
 class SK_API SkImageGenerator {
 public:
     /**
      *  The PixelRef which takes ownership of this SkImageGenerator
      *  will call the image generator's destructor.
@@ skipping 38 matching lines @@
      *
      *  @return false if anything goes wrong or if the image info is
      *          unsupported.
      */
     virtual bool getPixels(const SkImageInfo& info,
                            void* pixels,
                            size_t rowBytes) = 0;
 };
 
 #endif  // SkImageGenerator_DEFINED