Part 10 of cc/ directory shuffles: layers

Continuation of https://src.chromium.org/viewvc/chrome?view=rev&revision=188681

BUG=190824
TBR=enne@chromium.org, piman@chromium.org, jschuh@chromium.org, joth@chromium.org

Review URL: https://codereview.chromium.org/12916002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@188703 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 60 insertions, 0 deletions

diff --git a/cc/layers/video_frame_provider.h b/cc/layers/video_frame_provider.h
new file mode 100644
index 0000000..ecf0024
--- /dev/null
+++ b/cc/layers/video_frame_provider.h
@@ -0,0 +1,60 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CC_LAYERS_VIDEO_FRAME_PROVIDER_H_
+#define CC_LAYERS_VIDEO_FRAME_PROVIDER_H_
+
+#include "base/memory/ref_counted.h"
+
+namespace media {
+class VideoFrame;
+}
+
+namespace cc {
+
+// Threading notes: This class may be used in a multi threaded manner.
+// Specifically, the implementation may call getCurrentFrame() or
+// putCurrentFrame() from the compositor thread. If so, the caller is
+// responsible for making sure Client::didReceiveFrame and
+// Client::didUpdateMatrix are only called from this same thread.
+class VideoFrameProvider {
+ public:
+  virtual ~VideoFrameProvider() {}
+
+  class Client {
+   public:
+    // Provider will call this method to tell the client to stop using it.
+    // StopUsingProvider() may be called from any thread. The client should
+    // block until it has PutCurrentFrame() any outstanding frames.
+    virtual void StopUsingProvider() = 0;
+
+    // Notifies the provider's client that a call to GetCurrentFrame() will
+    // return new data.
+    virtual void DidReceiveFrame() = 0;
+
+    // Notifies the provider's client of a new UV transform matrix to be used.
+    virtual void DidUpdateMatrix(const float* matrix) = 0;
+  };
+
+  // May be called from any thread, but there must be some external guarantee
+  // that the provider is not destroyed before this call returns.
+  virtual void SetVideoFrameProviderClient(Client* client) = 0;
+
+  // This function places a lock on the current frame and returns a pointer to
+  // it. Calls to this method should always be followed with a call to
+  // PutCurrentFrame().
+  // Only the current provider client should call this function.
+  virtual scoped_refptr<media::VideoFrame> GetCurrentFrame() = 0;
+
+  // This function releases the lock on the video frame. It should always be
+  // called after GetCurrentFrame(). Frames passed into this method
+  // should no longer be referenced after the call is made. Only the current
+  // provider client should call this function.
+  virtual void PutCurrentFrame(
+      const scoped_refptr<media::VideoFrame>& frame) = 0;
+};
+
+}  // namespace cc
+
+#endif  // CC_LAYERS_VIDEO_FRAME_PROVIDER_H_