diff -r 000000000000 -r 6474c204b198 content/media/VideoFrameContainer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/VideoFrameContainer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,103 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 VIDEOFRAMECONTAINER_H_
+#define VIDEOFRAMECONTAINER_H_
+
+#include "mozilla/Mutex.h"
+#include "mozilla/TimeStamp.h"
+#include "gfxPoint.h"
+#include "nsCOMPtr.h"
+#include "nsAutoPtr.h"
+
+namespace mozilla {
+
+namespace dom {
+class HTMLMediaElement;
+}
+
+namespace layers {
+class Image;
+class ImageContainer;
+}
+
+/**
+ * This object is used in the decoder backend threads and the main thread
+ * to manage the "current video frame" state. This state includes timing data
+ * and an intrinsic size (see below).
+ * This has to be a thread-safe object since it's accessed by resource decoders
+ * and other off-main-thread components. So we can't put this state in the media
+ * element itself ... well, maybe we could, but it could be risky and/or
+ * confusing.
+ */
+class VideoFrameContainer {
+public:
+  typedef layers::ImageContainer ImageContainer;
+  typedef layers::Image Image;
+
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(VideoFrameContainer)
+
+  VideoFrameContainer(dom::HTMLMediaElement* aElement,
+                      already_AddRefed<ImageContainer> aContainer);
+  ~VideoFrameContainer();
+
+  // Call on any thread
+  void SetCurrentFrame(const gfxIntSize& aIntrinsicSize, Image* aImage,
+                       TimeStamp aTargetTime);
+  void ClearCurrentFrame(bool aResetSize = false);
+  // Reset the VideoFrameContainer
+  void Reset();
+  // Time in seconds by which the last painted video frame was late by.
+  // E.g. if the last painted frame should have been painted at time t,
+  // but was actually painted at t+n, this returns n in seconds. Threadsafe.
+  double GetFrameDelay();
+  // Call on main thread
+  enum {
+    INVALIDATE_DEFAULT,
+    INVALIDATE_FORCE
+  };
+  void Invalidate() { InvalidateWithFlags(INVALIDATE_DEFAULT); }
+  void InvalidateWithFlags(uint32_t aFlags);
+  ImageContainer* GetImageContainer();
+  void ForgetElement() { mElement = nullptr; }
+
+protected:
+  // Non-addreffed pointer to the element. The element calls ForgetElement
+  // to clear this reference when the element is destroyed.
+  dom::HTMLMediaElement* mElement;
+  nsRefPtr<ImageContainer> mImageContainer;
+
+  // mMutex protects all the fields below.
+  Mutex mMutex;
+  // The intrinsic size is the ideal size which we should render the
+  // ImageContainer's current Image at.
+  // This can differ from the Image's actual size when the media resource
+  // specifies that the Image should be stretched to have the correct aspect
+  // ratio.
+  gfxIntSize mIntrinsicSize;
+  // The time at which the current video frame should have been painted.
+  // Access protected by mVideoUpdateLock.
+  TimeStamp mPaintTarget;
+  // The delay between the last video frame being presented and it being
+  // painted. This is time elapsed after mPaintTarget until the most recently
+  // painted frame appeared on screen.
+  TimeDuration mPaintDelay;
+  // True when the intrinsic size has been changed by SetCurrentFrame() since
+  // the last call to Invalidate().
+  // The next call to Invalidate() will recalculate
+  // and update the intrinsic size on the element, request a frame reflow and
+  // then reset this flag.
+  bool mIntrinsicSizeChanged;
+  // True when the Image size has changed since the last time Invalidate() was
+  // called. When set, the next call to Invalidate() will ensure that the
+  // frame is fully invalidated instead of just invalidating for the image change
+  // in the ImageLayer.
+  bool mImageSizeChanged;
+};
+
+}
+
+#endif /* VIDEOFRAMECONTAINER_H_ */