chromeos: Turn off displays on suspend

ui/display/chromeos/x11/native_display_delegate_x11.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 "ui/display/chromeos/x11/native_display_delegate_x11.h"
 
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
 #include <X11/extensions/dpms.h>
 #include <X11/extensions/Xrandr.h>
@@ skipping 151 matching lines @@
 
 void NativeDisplayDelegateX11::SetBackgroundColor(uint32_t color_argb) {
   background_color_argb_ = color_argb;
 }
 
 void NativeDisplayDelegateX11::ForceDPMSOn() {
   CHECK(DPMSEnable(display_));
   CHECK(DPMSForceLevel(display_, DPMSModeOn));
 }
 
+void NativeDisplayDelegateX11::GetCachedDisplays(
+    const GetDisplaysCallback& callback) {
+  callback.Run(cached_outputs_.get());
+}
+
 void NativeDisplayDelegateX11::GetDisplays(
     const GetDisplaysCallback& callback) {
   CHECK(screen_) << "Server not grabbed";
 
   cached_outputs_.clear();
   std::set<RRCrtc> last_used_crtcs;
 
   InitModes();
   for (int i = 0; i < screen_->noutput; ++i) {
     RROutput output_id = screen_->outputs[i];
@@ skipping 473 matching lines @@
   XSetForeground(display_, gc, color.pixel);
   XSetFillStyle(display_, gc, FillSolid);
   int width = DisplayWidth(display_, DefaultScreen(display_));
   int height = DisplayHeight(display_, DefaultScreen(display_));
   XFillRectangle(display_, window_, gc, 0, 0, width, height);
   XFreeGC(display_, gc);
   XFreeColors(display_, colormap, &color.pixel, 1, 0);
 }
 
 }  // namespace ui