Image decoding: Remove deprecated image caching code

Source/platform/graphics/DiscardablePixelRef.h

Index: Source/platform/graphics/DiscardablePixelRef.h
diff --git a/Source/platform/graphics/DiscardablePixelRef.h b/Source/platform/graphics/DiscardablePixelRef.h
deleted file mode 100644
index 99f18bde4b2f13411b7a99a4cf1c56c5cad5718b..0000000000000000000000000000000000000000
--- a/Source/platform/graphics/DiscardablePixelRef.h
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * 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:
- * 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
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef DiscardablePixelRef_h
-#define DiscardablePixelRef_h
-
-#include "SkBitmap.h"
-#include "SkPixelRef.h"
-
-#include "platform/PlatformExport.h"
-#include "public/platform/WebDiscardableMemory.h"
-#include "wtf/OwnPtr.h"
-#include "wtf/PassOwnPtr.h"
-
-namespace blink {
-
-// Class for allocating the DiscardablePixelRef object.
-class PLATFORM_EXPORT DiscardablePixelRefAllocator : public SkBitmap::Allocator {
-    // SkBitmap::Allocator implementation. The discardable memory allocated
-    // after this call is locked and will not be purged until next
-    // onUnlockPixels().
-    virtual bool allocPixelRef(SkBitmap*, SkColorTable*) OVERRIDE;
-};
-
-// PixelRef object whose memory can be discarded when pixels are unlocked.
-class PLATFORM_EXPORT DiscardablePixelRef : public SkPixelRef {
-public:
-    DiscardablePixelRef(const SkImageInfo&, size_t rowBytes, PassOwnPtr<SkMutex>);
-    virtual ~DiscardablePixelRef();
-
-    static bool isDiscardable(SkPixelRef*);
-    bool allocAndLockDiscardableMemory(size_t);
-
-protected:
-    // SkPixelRef implementation.
-    virtual bool onNewLockPixels(LockRec*) OVERRIDE;
-    virtual void onUnlockPixels() OVERRIDE;
-
-private:
-    void* m_lockedMemory;
-    OwnPtr<WebDiscardableMemory> m_discardable;
-    OwnPtr<SkMutex> m_mutex;
-    size_t m_rowBytes;
-};
-
-} // namespace blink
-
-#endif