[Ozone] Adding display related IPC messages

ui/display/types/display_constants.h

 // 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.
 
 #ifndef UI_DISPLAY_TYPES_DISPLAY_CONSTANTS_H_
 #define UI_DISPLAY_TYPES_DISPLAY_CONSTANTS_H_
 
 namespace ui {
 
 // Used to describe the state of a multi-display configuration.
 enum MultipleDisplayState {
   MULTIPLE_DISPLAY_STATE_INVALID,
   MULTIPLE_DISPLAY_STATE_HEADLESS,
   MULTIPLE_DISPLAY_STATE_SINGLE,
   MULTIPLE_DISPLAY_STATE_DUAL_MIRROR,
   MULTIPLE_DISPLAY_STATE_DUAL_EXTENDED,
 };
 
 // Video output types.
 enum DisplayConnectionType {
   DISPLAY_CONNECTION_TYPE_NONE = 0,
   DISPLAY_CONNECTION_TYPE_UNKNOWN = 1 << 0,
   DISPLAY_CONNECTION_TYPE_INTERNAL = 1 << 1,
   DISPLAY_CONNECTION_TYPE_VGA = 1 << 2,
   DISPLAY_CONNECTION_TYPE_HDMI = 1 << 3,
   DISPLAY_CONNECTION_TYPE_DVI = 1 << 4,
   DISPLAY_CONNECTION_TYPE_DISPLAYPORT = 1 << 5,
   DISPLAY_CONNECTION_TYPE_NETWORK = 1 << 6,
+
+  // Update this when adding a new type.
+  DISPLAY_CONNECTION_TYPE_LAST = DISPLAY_CONNECTION_TYPE_NETWORK
 };
 
 // Content protection methods applied on video output.
 enum ContentProtectionMethod {
   CONTENT_PROTECTION_METHOD_NONE = 0,
   CONTENT_PROTECTION_METHOD_HDCP = 1 << 0,
 };
 
 // HDCP protection state.
 enum HDCPState { HDCP_STATE_UNDESIRED, HDCP_STATE_DESIRED, HDCP_STATE_ENABLED };
 
 // Color calibration profiles. Don't change the order, and edit
 // tools/metrics/histograms/histograms.xml when a new item is added.
 enum ColorCalibrationProfile {
   COLOR_PROFILE_STANDARD,
   COLOR_PROFILE_DYNAMIC,
   COLOR_PROFILE_MOVIE,
   COLOR_PROFILE_READING,
   NUM_COLOR_PROFILES,
 };
 
 }  // namespace ui
 
 #endif  // UI_DISPLAY_TYPES_DISPLAY_CONSTANTS_H_