mustash: Implement basic input event routing in renderer

content/renderer/render_widget_mus_connection.h

Index: content/renderer/render_widget_mus_connection.h
diff --git a/content/renderer/render_widget_mus_connection.h b/content/renderer/render_widget_mus_connection.h
index b522a9f52fc7f9cb45392366d1970ca5dc434bfc..b3aaaf0e4273c6f7307b1e94550cb26b8e926806 100644
--- a/content/renderer/render_widget_mus_connection.h
+++ b/content/renderer/render_widget_mus_connection.h
@@ -7,45 +7,40 @@
 
 #include "base/macros.h"
 #include "cc/output/output_surface.h"
-#include "components/mus/public/cpp/window.h"
-#include "components/mus/public/cpp/window_observer.h"
 #include "components/mus/public/cpp/window_surface.h"
-#include "components/mus/public/cpp/window_tree_connection.h"
-#include "components/mus/public/cpp/window_tree_delegate.h"
-#include "mojo/public/cpp/bindings/binding.h"
+#include "content/renderer/compositor_mus_connection.h"
 
 namespace content {
 
-class RenderWidgetMusConnection : public mus::WindowTreeDelegate,
-                                  public mus::WindowObserver {
- public:
-  RenderWidgetMusConnection(
-      int routing_id);
-  ~RenderWidgetMusConnection() override;
+class InputHandlerManager;
 
-  // Connect to a WindowTreeClient request.
-  void Connect(mojo::InterfaceRequest<mus::mojom::WindowTreeClient> request);
+// Use on main thread.
+class RenderWidgetMusConnection {
+ public:
+  // Bind to a WindowTreeClient request.
+  void Bind(mojo::InterfaceRequest<mus::mojom::WindowTreeClient> request);
 
   // Create a cc output surface.
   scoped_ptr<cc::OutputSurface> CreateOutputSurface();
 
+  static RenderWidgetMusConnection* Get(int routing_id);
+
   // Get the connection from a routing_id, if the connection doesn't exist,
   // a new connection will be created.
-  static RenderWidgetMusConnection* Get(int routing_id);
+  static RenderWidgetMusConnection* GetOrCreate(int routing_id);
 
  private:
-  // WindowTreeDelegate implementation:
-  void OnConnectionLost(mus::WindowTreeConnection* connection) override;
-  void OnEmbed(mus::Window* root) override;
-  void OnUnembed() override;
-  void OnWindowBoundsChanged(mus::Window* window,
-                             const gfx::Rect& old_bounds,
-                             const gfx::Rect& new_bounds) override;
+  friend class CompositorMusConnection;
+
+  explicit RenderWidgetMusConnection(int routing_id);
+  ~RenderWidgetMusConnection();
+
+  void OnConnectionLost();
+  void OnWindowInputEvent(scoped_ptr<blink::WebInputEvent> input_event);
 
   const int routing_id_;
-  bool connected_;
-  mus::Window* root_;
   scoped_ptr<mus::WindowSurfaceBinding> window_surface_binding_;
+  scoped_refptr<CompositorMusConnection> compositor_mus_connection_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetMusConnection);
 };