Don't cache any SkBitmaps in DeferredImageDecoder

Source/platform/image-decoders/ImageAnimation.h

 /*
- * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ * Copyright (C) 2015 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 ActiveDOMObject_h
-#define ActiveDOMObject_h
-
-#include "core/dom/ContextLifecycleObserver.h"
-#include "wtf/Assertions.h"
+#ifndef ImageAnimation_h
+#define ImageAnimation_h
 
 namespace blink {
 
-class ActiveDOMObject : public ContextLifecycleObserver {
-public:
-    ActiveDOMObject(ExecutionContext*);
-
-    // suspendIfNeeded() should be called exactly once after object construction to synchronize
-    // the suspend state with that in ExecutionContext.
-    void suspendIfNeeded();
-#if ENABLE(ASSERT)
-    bool suspendIfNeededCalled() const { return m_suspendIfNeededCalled; }
-#endif
-
-    // Should return true if there's any pending asynchronous activity, and so
-    // this object must not be garbage collected.
-    virtual bool hasPendingActivity() const;
-
-    // These methods have an empty default implementation so that subclasses
-    // which don't need special treatment can skip implementation.
-    virtual void suspend();
-    virtual void resume();
-    virtual void stop();
-
-    void didMoveToNewExecutionContext(ExecutionContext*);
-
-protected:
-    virtual ~ActiveDOMObject();
-
-private:
-#if ENABLE(ASSERT)
-    bool m_suspendIfNeededCalled;
-#endif
-};
+// GIF and WebP support animation. The explanation below is in terms of GIF,
+// but the same constants are used for WebP, too.
+// GIFs have an optional 16-bit unsigned loop count that describes how an
+// animated GIF should be cycled.  If the loop count is absent, the animation
+// cycles once; if it is 0, the animation cycles infinitely; otherwise the
+// animation plays n + 1 cycles (where n is the specified loop count).  If the
+// GIF decoder defaults to cAnimationLoopOnce in the absence of any loop count
+// and translates an explicit "0" loop count to cAnimationLoopInfinite, then we
+// get a couple of nice side effects:
+//   * By making cAnimationLoopOnce be 0, we allow the animation cycling code in
+//     BitmapImage.cpp to avoid special-casing it, and simply treat all
+//     non-negative loop counts identically.
+//   * By making the other two constants negative, we avoid conflicts with any
+//     real loop count values.
+const int cAnimationLoopOnce = 0;
+const int cAnimationLoopInfinite = -1;
+const int cAnimationNone = -2;
 
 } // namespace blink
 
-#endif // ActiveDOMObject_h
+#endif