SkOnce: add option to call another cleanup function once at exit.

src/core/SkScaledImageCache.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkScaledImageCache.h"
 #include "SkMipMap.h"
 #include "SkOnce.h"
@@ skipping 665 matching lines @@
     SkDebugf("SkScaledImageCache: count=%d bytes=%d locked=%d %s\n",
              fCount, fBytesUsed, locked,
              fDiscardableFactory ? "discardable" : "malloc");
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 #include "SkThread.h"
 
 SK_DECLARE_STATIC_MUTEX(gMutex);
+static SkScaledImageCache* gScaledImageCache = NULL;
+static void cleanup_gScaledImageCache() { SkDELETE(gScaledImageCache); }
 
-static void create_cache(SkScaledImageCache** cache) {
+static void create_cache(int) {
 #ifdef SK_USE_DISCARDABLE_SCALEDIMAGECACHE
-    *cache = SkNEW_ARGS(SkScaledImageCache, (SkDiscardableMemory::Create));
+    gScaledImageCache = SkNEW_ARGS(SkScaledImageCache, (SkDiscardableMemory::Create));
 #else
-    *cache = SkNEW_ARGS(SkScaledImageCache, (SK_DEFAULT_IMAGE_CACHE_LIMIT));
+    gScaledImageCache = SkNEW_ARGS(SkScaledImageCache, (SK_DEFAULT_IMAGE_CACHE_LIMIT));
 #endif
 }
 
 static SkScaledImageCache* get_cache() {
-    static SkScaledImageCache* gCache(NULL);
-    SK_DECLARE_STATIC_ONCE(create_cache_once);
-    SkOnce(&create_cache_once, create_cache, &gCache);
-    SkASSERT(NULL != gCache);
-    return gCache;
+    SK_DECLARE_STATIC_ONCE(once);
+    SkOnce(&once, create_cache, 0, cleanup_gScaledImageCache);
+    SkASSERT(NULL != gScaledImageCache);
+    return gScaledImageCache;
 }
 
 
 SkScaledImageCache::ID* SkScaledImageCache::FindAndLock(
                                 uint32_t pixelGenerationID,
                                 int32_t width,
                                 int32_t height,
                                 SkBitmap* scaled) {
     SkAutoMutexAcquire am(gMutex);
     return get_cache()->findAndLock(pixelGenerationID, width, height, scaled);
@@ skipping 77 matching lines @@
     return SkScaledImageCache::GetBytesUsed();
 }
 
 size_t SkGraphics::GetImageCacheByteLimit() {
     return SkScaledImageCache::GetByteLimit();
 }
 
 size_t SkGraphics::SetImageCacheByteLimit(size_t newLimit) {
     return SkScaledImageCache::SetByteLimit(newLimit);
 }