Chrome OS: Ash support for >=3 displays.

ash/display/screen_ash.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 "ash/display/screen_ash.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/display/display_manager.h"
 #include "ash/root_window_controller.h"
 #include "ash/root_window_settings.h"
@@ skipping 143 matching lines @@
                                            const gfx::Rect& rect) {
   gfx::Point point = rect.origin();
   aura::client::GetScreenPositionClient(window->GetRootWindow())->
       ConvertPointFromScreen(window, &point);
   return gfx::Rect(point, rect.size());
 }
 
 // static
 const gfx::Display& ScreenAsh::GetSecondaryDisplay() {
   DisplayManager* display_manager = GetDisplayManager();
-  CHECK_EQ(2U, display_manager->GetNumDisplays());
+  CHECK_LE(2U, display_manager->GetNumDisplays());
   return display_manager->GetDisplayAt(0).id() ==
       Shell::GetScreen()->GetPrimaryDisplay().id() ?
       display_manager->GetDisplayAt(1) : display_manager->GetDisplayAt(0);
 }
 
 // static
 const gfx::Display& ScreenAsh::GetDisplayForId(int64 display_id) {
   return GetDisplayManager()->GetDisplayForId(display_id);
 }
 
@@ skipping 85 matching lines @@
 
 void ScreenAsh::RemoveObserver(gfx::DisplayObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 gfx::Screen* ScreenAsh::CloneForShutdown() {
   return new ScreenForShutdown(this);
 }
 
 }  // namespace ash