Mus+Ash: Unified BeginFrame Skeleton

cc/ipc/mojo_compositor_frame_sink.mojom

 // Copyright 2016 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.
 
 module cc.mojom;
 
+import "cc/ipc/begin_frame_args.mojom";
 import "cc/ipc/compositor_frame.mojom";
+import "cc/ipc/frame_sink_id.mojom";
 import "cc/ipc/returned_resource.mojom";
 
 // A MojoCompositorFrameSink is an interface for receiving CompositorFrame
 // structs. A CompositorFrame contains the complete output meant for display.
 // Each time a client has a graphical update, and receives an OnBeginFrame, it
 // is responsible for creating a CompositorFrame to update its portion of the
 // screen.
 interface MojoCompositorFrameSink {
   // Lets the display compositor know that the client wishes to receive the next
   // BeginFrame event.
@@ skipping 13 matching lines @@
 interface MojoCompositorFrameSinkClient {
   // Notification that the previous CompositorFrame given to
   // SubmitCompositorFrame() has been processed and that another frame
   // can be submitted. This provides backpressure from the display compositor
   // so that frames are submitted only at the rate it can handle them.
   // TODO(fsamuel): This method ought not be necessary with unified BeginFrame.
   // However, there's a fair amount of cleanup and refactoring necessary to get
   // rid of it.
   DidReceiveCompositorFrameAck();
 
+  // Notification for the client to generate a CompositorFrame.
+  OnBeginFrame(BeginFrameArgs args);
+
   // Returns resources sent to SubmitCompositorFrame to be reused or freed.
   ReclaimResources(ReturnedResourceArray resources);
 };
+
+// MojoCompositorFrameSinkPrivate is used by the display compositor host to set
+// up BeginFrameSource hierarchies.  This API lives in SurfaceManager but is
+// called from here in order to ensure that hierarchy registration does not race
+// CompositorFrameSink creation.
+interface MojoCompositorFrameSinkPrivate {
+  AddChildFrameSink(FrameSinkId child_frame_sink_id);
+  RemoveChildFrameSink(FrameSinkId child_frame_sink_id);
+};