Start of display management for mus

components/mus/public/interfaces/display.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 mus.mojom;
+
+import "components/mus/public/interfaces/window_manager_constants.mojom";
+
+interface DisplayManagerObserver {
+  // Sent when the observer is added. Gives the initial state.
+  OnDisplays(array<Display> displays);
+
+  // The specified set of displays has changed in some way. This is used both
+  // when a new display is added, or when a property of a display changes.
+  // |displays| does not necessarily contain the complete set of displays,
+  // only those that changed.
+  OnDisplaysChanged(array<Display> displays);
+
+  // An existing display was removed.
+  OnDisplayRemoved(int64 id);
+};
+
+interface DisplayManager {
+  AddObserver(DisplayManagerObserver observer);
+};