Make SkBitmapCache remove invalid bitmaps from the SkResourceCache.

src/core/SkResourceCache.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 SkResourceCache_DEFINED
 #define SkResourceCache_DEFINED
 
@@ skipping 80 matching lines @@
 
     /*
      *  The following static methods are thread-safe wrappers around a global
      *  instance of this cache.
      */
 
     static const Rec* FindAndLock(const Key& key);
     static const Rec* AddAndLock(Rec*);
     static void Add(Rec*);
     static void Unlock(ID);
+    static void Remove(ID);
 
     static size_t GetTotalBytesUsed();
     static size_t GetTotalByteLimit();
     static size_t SetTotalByteLimit(size_t newLimit);
 
     static size_t SetSingleAllocationByteLimit(size_t);
     static size_t GetSingleAllocationByteLimit();
 
     /**
      * Use this allocator for bitmaps, so they can use ashmem when available.
@@ skipping 22 matching lines @@
      *  byteLimit, purging automatically when a new image is added to the cache
      *  that pushes the total bytesUsed over the limit. Note: The limit can be
      *  changed at runtime with setTotalByteLimit.
      */
     explicit SkResourceCache(size_t byteLimit);
     ~SkResourceCache();
 
     const Rec* findAndLock(const Key& key);
     const Rec* addAndLock(Rec*);
     void add(Rec*);
+    void remove(Rec*);
 
     /**
      *  Given a non-null ID ptr returned by either findAndLock or addAndLock,
      *  this releases the associated resources to be available to be purged
      *  if needed. After this, the cached bitmap should no longer be
      *  referenced by the caller.
      */
     void unlock(ID);
 
     size_t getTotalBytesUsed() const { return fTotalBytesUsed; }
@@ skipping 29 matching lines @@
 
     DiscardableFactory  fDiscardableFactory;
     // the allocator is NULL or one that matches discardables
     SkBitmap::Allocator* fAllocator;
 
     size_t  fTotalBytesUsed;
     size_t  fTotalByteLimit;
     size_t  fSingleAllocationByteLimit;
     int     fCount;
 
-    void purgeRec(Rec*);
     void purgeAsNeeded();
 
     // linklist management
     void moveToHead(Rec*);
     void addToHead(Rec*);
     void detach(Rec*);
 
     void init();    // called by constructors
 
 #ifdef SK_DEBUG
     void validate() const;
 #else
     void validate() const {}
 #endif
 };
 #endif