Implement aura::WindowPortMus::CreateCompositorFrameSink()

services/ui/public/interfaces/window_tree.mojom

 // Copyright 2014 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 ui.mojom;
 
 import "cc/ipc/frame_sink_id.mojom";
 import "cc/ipc/local_surface_id.mojom";
 import "cc/ipc/surface_id.mojom";
 import "cc/ipc/surface_info.mojom";
@@ skipping 297 matching lines @@
                   gfx.mojom.Point screen_location,
                   map<string, array<uint8>> drag_data,
                   skia.mojom.Bitmap? drag_image,
                   gfx.mojom.Vector2d drag_image_offset,
                   uint32 drag_operation,
                   PointerKind source);
 
   // Called by the client to cancel any in progress drag drop operation. This
   // will result in a change completed for the underlying change.
   CancelDragDrop(uint32 window_id);
+
+  // Get the FrameSinkId for the given window_id. The OnFrameSinkIdAllocated()
+  // will be called with the FrameSinkId.
+  GetFrameSinkId(uint32 window_id);

[Fady Samuel, 2017/05/18 16:48:51]

Who calls this? The embedder? And then the embeddee gets OnFrameSInkIdAllocated?

[Peng, 2017/05/18 19:37:59]

Removed, since the SurfaceInfo will be send to client via
OnWindowSurfaceChanged().

 };
 
 // Changes to windows are not sent to the connection that originated the
 // change. For example, if connection 1 changes the bounds of a window by
 // calling SetWindowBounds(), connection 1 does not receive
 // OnWindowBoundsChanged().
 interface WindowTreeClient {
   // Invoked when the client application has been embedded at |root|.
   // See Embed() on WindowTree for more details. |tree| will be a handle back to
   // the window manager service, unless the connection is to the root connection
@@ skipping 16 matching lines @@
   OnEmbeddedAppDisconnected(uint32 window);
 
   // Sent when another connection is embedded in the Window this connection was
   // previously embedded in. See Embed() for more information.
   OnUnembed(uint32 window);
 
   // Sent when capture changes. This is not sent if the client initiated the
   // change.
   OnCaptureChanged(uint32 new_capture, uint32 old_capture);
 
-  // This is called on the owner of a window when it embeds a client in it,
-  // which includes the window manager creating a new window at the request of
-  // another client.
+  // This is called in response to GetFrameSinkId(), or on the owner of a window
+  // when it embeds a client in it, which includes the window manager creating
+  // a new window at the request of another client.
   OnFrameSinkIdAllocated(uint32 window, cc.mojom.FrameSinkId frame_sink_id);
 
   // Called in response to NewTopLevelWindow() successfully completing.
   // |parent_drawn| is true if the parent of the window is drawn, see
   // OnDrawnStateChanged() for details. |display_id| identifies the display this
   // window is on. If the top level window has a size, |local_surface_id|
   // identifies the ID to use to submit CompositorFrames.
   OnTopLevelCreated(uint32 change_id,
                     WindowData data,
                     int64 display_id,
@@ skipping 159 matching lines @@
   // See description of WindowManager for details.
   GetWindowManager(associated WindowManager& internal);
 };
 
 // Mus provides this interface as a way for clients to connect and obtain a
 // WindowTree handle with a supplied WindowTreeClient handle. The
 // WindowTreeClient has no roots, use NewTopLevelWindow() to create one.
 interface WindowTreeFactory {
   CreateWindowTree(WindowTree& tree_request, WindowTreeClient client);
 };