Use skia discardable memory for decoded images on Android.

Source/platform/graphics/DeferredImageDecoder.cpp

 /*
  * Copyright (C) 2012 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 66 matching lines @@
 {
     return bitmap.pixelRef()
         && bitmap.pixelRef()->getURI()
         && (!memcmp(bitmap.pixelRef()->getURI(), labelLazyDecoded, sizeof(labelLazyDecoded))
             || !memcmp(bitmap.pixelRef()->getURI(), labelDiscardable, sizeof(labelDiscardable)));
 }
 
 void DeferredImageDecoder::setEnabled(bool enabled)
 {
     s_enabled = enabled;
-#if !OS(ANDROID)
-    // FIXME: This code is temporary to enable discardable memory for
-    // non-Android platforms. In the future all platforms will be
-    // the same and we can remove this code.
+    // FIXME: Remove all non-discardable memory related code now that this is
+    // used on all platforms.
     s_skiaDiscardableMemoryEnabled = enabled;
     if (enabled)
         ImageDecodingStore::setImageCachingEnabled(false);
-#endif
 }
 
 bool DeferredImageDecoder::enabled()
 {
     return s_enabled;
 }
 
 String DeferredImageDecoder::filenameExtension() const
 {
     return m_actualDecoder ? m_actualDecoder->filenameExtension() : m_filenameExtension;
@@ skipping 228 matching lines @@
     return bitmap;
 }
 
 bool DeferredImageDecoder::hotSpot(IntPoint& hotSpot) const
 {
     // TODO: Implement.
     return m_actualDecoder ? m_actualDecoder->hotSpot(hotSpot) : false;
 }
 
 } // namespace WebCore