Add FakeDisplayDelegate for off device usage.

ui/display/display_switches.cc

 // 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.
 
 #include "build/build_config.h"
 #include "ui/display/display_switches.h"
 
 namespace switches {
 
 // TODO(rjkroege): Some of these have an "ash" prefix. When ChromeOS startup
 // scripts have been updated, the leading "ash" prefix should be removed.
 
-// Overrides the device scale factor for the browser UI and the contents.
-const char kForceDeviceScaleFactor[] = "force-device-scale-factor";
-
-// Specifies the layout mode and offsets for the secondary display for
-// testing. The format is "<t|r|b|l>,<offset>" where t=TOP, r=RIGHT,
-// b=BOTTOM and L=LEFT. For example, 'r,-100' means the secondary display
-// is positioned on the right with -100 offset. (above than primary)
-const char kSecondaryDisplayLayout[] = "secondary-display-layout";
-
 // Enables software based mirroring.
 const char kEnableSoftwareMirroring[] = "ash-enable-software-mirroring";
 
-// Uses the 1st display in --ash-host-window-bounds as internal display.
-// This is for debugging on linux desktop.
-const char kUseFirstDisplayAsInternal[] = "ash-use-first-display-as-internal";
+// Overrides the device scale factor for the browser UI and the contents.
+const char kForceDeviceScaleFactor[] = "force-device-scale-factor";
 
 // Sets a window size, optional position, and optional scale factor.
 // "1024x768" creates a window of size 1024x768.
 // "100+200-1024x768" positions the window at 100,200.
 // "1024x768*2" sets the scale factor to 2 for a high DPI display.
 // "800,0+800-800x800" for two displays at 800x800 resolution.
 // "800,0+800-800x800,0+1600-800x800" for three displays at 800x800 resolution.
 const char kHostWindowBounds[] = "ash-host-window-bounds";
 
+// Specifies the layout mode and offsets for the secondary display for
+// testing. The format is "<t|r|b|l>,<offset>" where t=TOP, r=RIGHT,
+// b=BOTTOM and L=LEFT. For example, 'r,-100' means the secondary display
+// is positioned on the right with -100 offset. (above than primary)
+const char kSecondaryDisplayLayout[] = "secondary-display-layout";
+
+// Specifies the initial screen configuration, or state of all displays, for
+// FakeDisplayDelegate, see class for format details.
+const char kScreenConfig[] = "screen-config";
+
+// Uses the 1st display in --ash-host-window-bounds as internal display.
+// This is for debugging on linux desktop.
+const char kUseFirstDisplayAsInternal[] = "ash-use-first-display-as-internal";

[oshima, 2016/09/16 20:50:00]

you may remove "ash-". 

[kylechar, 2016/09/16 20:59:15]

Done.

+
 #if defined(OS_CHROMEOS)
 const char kDisableDisplayColorCalibration[] =
     "disable-display-color-calibration";
 
 // Enables unified desktop mode.
 const char kEnableUnifiedDesktop[] = "ash-enable-unified-desktop";
 #endif
 
 }  // namespace switches