Cheaper thread-safe atomic initialization of static references.

Source/web/WebImageCache.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 19 matching lines @@
 
 #include "config.h"
 #include "public/web/WebImageCache.h"
 
 #include "platform/graphics/ImageDecodingStore.h"
 
 namespace blink {
 
 void WebImageCache::setCacheLimitInBytes(size_t size)
 {
-    ImageDecodingStore::instance()->setCacheLimitInBytes(size);
+    ImageDecodingStore::instance().setCacheLimitInBytes(size);
 }
 
 void WebImageCache::clear()
 {
-    if (ImageDecodingStore::instance())
-        ImageDecodingStore::instance()->clear();
+    ImageDecodingStore::instance().clear();
 }
 
 size_t WebImageCache::memoryUsageInBytes()
 {
-    return ImageDecodingStore::instance()->memoryUsageInBytes();
+    return ImageDecodingStore::instance().memoryUsageInBytes();
 }
 
 unsigned WebImageCache::cacheEntries()
 {
-    return ImageDecodingStore::instance()->cacheEntries();
+    return ImageDecodingStore::instance().cacheEntries();
 }
 
 }  // namespace blink