Chrome OS: Ash support for >=3 displays.

ui/display/chromeos/x11/native_display_delegate_x11.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_CHROMEOS_X11_NATIVE_DISPLAY_DELEGATE_X11_H_
 #define UI_DISPLAY_CHROMEOS_X11_NATIVE_DISPLAY_DELEGATE_X11_H_
 
 #include <stdint.h>
 
 #include <map>
+#include <set>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/observer_list.h"
 #include "ui/display/display_export.h"
 #include "ui/display/types/native_display_delegate.h"
 #include "ui/gfx/geometry/point.h"
@@ skipping 78 matching lines @@
  private:
   class HelperDelegateX11;
 
   // Parses all the modes made available by |screen_|.
   void InitModes();
 
   // Helper method for GetOutputs() that returns an OutputSnapshot struct based
   // on the passed-in information.
   DisplaySnapshotX11* InitDisplaySnapshot(RROutput id,
                                           XRROutputInfo* info,
-                                          RRCrtc* last_used_crtc,
+                                          std::set<RRCrtc>* last_used_crtcs,
                                           int index);
 
   // Destroys unused CRTCs.
   void DestroyUnusedCrtcs();
 
   // Parks used CRTCs in a way which allows a framebuffer resize. This is faster
   // than turning them off, resizing, then turning them back on.
   // |min_screen_size| represent the smallest size between the current
   // framebuffer size and the requested framebuffer size.
   void UpdateCrtcsForNewFramebuffer(const gfx::Size& min_screen_size);
@@ skipping 35 matching lines @@
 
   // A background color used during boot time + multi displays.
   uint32_t background_color_argb_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeDisplayDelegateX11);
 };
 
 }  // namespace ui
 
 #endif  // UI_DISPLAY_CHROMEOS_X11_NATIVE_DISPLAY_DELEGATE_X11_H_