Pulls display related changes from mojo to chrome

mojo/services/view_manager/focus_controller.h

Index: mojo/services/view_manager/focus_controller.h
diff --git a/mojo/services/view_manager/focus_controller.h b/mojo/services/view_manager/focus_controller.h
new file mode 100644
index 0000000000000000000000000000000000000000..3bdd060ff3c6ba81a5d551775bd9924b289abba5
--- /dev/null
+++ b/mojo/services/view_manager/focus_controller.h
@@ -0,0 +1,53 @@
+// Copyright 2015 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 SERVICES_VIEW_MANAGER_FOCUS_CONTROLLER_H_
+#define SERVICES_VIEW_MANAGER_FOCUS_CONTROLLER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "mojo/services/view_manager/server_view_drawn_tracker_observer.h"
+
+namespace view_manager {
+
+class FocusControllerDelegate;
+class ServerView;
+class ServerViewDrawnTracker;
+
+// Tracks a focused view. Focus is moved to another view when the drawn state
+// of the focused view changes and the delegate is notified.
+class FocusController : public ServerViewDrawnTrackerObserver {
+ public:
+  FocusController(FocusControllerDelegate* delegate, ServerView* root);
+  ~FocusController() override;
+
+  // Sets the focused view. Does nothing if |view| is currently focused. This
+  // does not notify the delegate.
+  void SetFocusedView(ServerView* view);
+  ServerView* GetFocusedView();
+
+ private:
+  // Describes the source of the change.
+  enum ChangeSource {
+    CHANGE_SOURCE_EXPLICIT,
+    CHANGE_SOURCE_DRAWN_STATE_CHANGED,
+  };
+
+  // Implementation of SetFocusedView().
+  void SetFocusedViewImpl(ServerView* view, ChangeSource change_source);
+
+  // ServerViewDrawnTrackerObserver:
+  void OnDrawnStateChanged(ServerView* ancestor,
+                           ServerView* view,
+                           bool is_drawn) override;
+
+  FocusControllerDelegate* delegate_;
+  ServerView* root_;
+  scoped_ptr<ServerViewDrawnTracker> drawn_tracker_;
+
+  DISALLOW_COPY_AND_ASSIGN(FocusController);
+};
+
+}  // namespace view_manager
+
+#endif  // SERVICES_VIEW_MANAGER_FOCUS_CONTROLLER_H_