diff -r 000000000000 -r 6474c204b198 image/src/FrozenImage.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/image/src/FrozenImage.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,71 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_IMAGELIB_FROZENIMAGE_H_
+#define MOZILLA_IMAGELIB_FROZENIMAGE_H_
+
+#include "ImageWrapper.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/RefPtr.h"
+
+namespace mozilla {
+namespace image {
+
+/**
+ * An Image wrapper that disables animation, freezing the image at its first
+ * frame. It does this using two strategies. If this is the only instance of the
+ * image, animation will never start, because IncrementAnimationConsumers is
+ * ignored. If there is another instance that is animated, that's still OK,
+ * because any imgIContainer method that is affected by animation gets its
+ * aWhichFrame argument set to FRAME_FIRST when it passes through FrozenImage.
+ *
+ * XXX(seth): There a known (performance, not correctness) issue with
+ * GetImageContainer. See the comments for that method for more information.
+ */
+class FrozenImage : public ImageWrapper
+{
+  typedef mozilla::gfx::SourceSurface SourceSurface;
+
+public:
+  NS_DECL_ISUPPORTS
+
+  virtual ~FrozenImage() { }
+
+  virtual nsIntRect FrameRect(uint32_t aWhichFrame) MOZ_OVERRIDE;
+  virtual void IncrementAnimationConsumers() MOZ_OVERRIDE;
+  virtual void DecrementAnimationConsumers() MOZ_OVERRIDE;
+
+  NS_IMETHOD GetAnimated(bool* aAnimated) MOZ_OVERRIDE;
+  NS_IMETHOD_(TemporaryRef<SourceSurface>)
+    GetFrame(uint32_t aWhichFrame, uint32_t aFlags) MOZ_OVERRIDE;
+  NS_IMETHOD_(bool) FrameIsOpaque(uint32_t aWhichFrame) MOZ_OVERRIDE;
+  NS_IMETHOD GetImageContainer(layers::LayerManager* aManager,
+                               layers::ImageContainer** _retval) MOZ_OVERRIDE;
+  NS_IMETHOD Draw(gfxContext* aContext,
+                  GraphicsFilter aFilter,
+                  const gfxMatrix& aUserSpaceToImageSpace,
+                  const gfxRect& aFill,
+                  const nsIntRect& aSubimage,
+                  const nsIntSize& aViewportSize,
+                  const SVGImageContext* aSVGContext,
+                  uint32_t aWhichFrame,
+                  uint32_t aFlags) MOZ_OVERRIDE;
+  NS_IMETHOD_(void) RequestRefresh(const mozilla::TimeStamp& aTime) MOZ_OVERRIDE;
+  NS_IMETHOD GetAnimationMode(uint16_t* aAnimationMode) MOZ_OVERRIDE;
+  NS_IMETHOD SetAnimationMode(uint16_t aAnimationMode) MOZ_OVERRIDE;
+  NS_IMETHOD ResetAnimation() MOZ_OVERRIDE;
+  NS_IMETHOD_(float) GetFrameIndex(uint32_t aWhichFrame) MOZ_OVERRIDE;
+
+protected:
+  FrozenImage(Image* aImage) : ImageWrapper(aImage) { }
+
+private:
+  friend class ImageOps;
+};
+
+} // namespace image
+} // namespace mozilla
+
+#endif // MOZILLA_IMAGELIB_FROZENIMAGE_H_