Mus: Implement GpuMain mojo interface

cc/ipc/display_compositor.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/frame_sink_id.mojom";
 import "cc/ipc/mojo_compositor_frame_sink.mojom";
 import "cc/ipc/surface_id.mojom";
 import "cc/ipc/surface_sequence.mojom";
 import "gpu/ipc/common/surface_handle.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 
+// This is the main interface that the DisplayCompositor host uses
+// to connect to the Display Compositor service.
+interface DisplayCompositorFactory {
+  CreateDisplayCompositor(DisplayCompositor& display_compositor,
+                          DisplayCompositorClient display_compositor_client);
+};
+
 // The DisplayCompositor interface is a privileged interface that allows
 // the display compositor host (browser or window server) to create
 // CompositorFrameSinks. Clients acquire a CompositorFrameSink connection
 // through the display compositor host. Clients request a
 // MojoCompositorFrameSink interface, and implement a
 // MojoCompositorFrameSinkClient interface. The display compositor host
 // holds one or more root CompositorFrameSinks that are tied to a valid
 // |surface_handle|. All other CompositorFrameSinks are offscreen. FrameSinkIds
 // are fixed for a given client and are determined ahead of time. Thus, a client
 // will typically simply request a CompositorFrameSink from the display
@@ skipping 20 matching lines @@
 // Compositor Host, a stable, and privileged peer service to the display
 // compositor. The display compositor host is either the browser process in
 // Chrome or the window server process.
 interface DisplayCompositorClient {
   // Called by the display compositor immediately upon receiving a
   // CompositorFrame with a new SurfaceId for the first time.
   OnSurfaceCreated(cc.mojom.SurfaceId surface_id,
                    gfx.mojom.Size frame_size,
                    float device_scale_factor);
 };