Add ability to set resolution on external display

ash/display/display_util_x11.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright (c) 2013 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 ASH_DISPLAY_DISPLAY_CHANGE_OBSERVER_X11_H
-#define ASH_DISPLAY_DISPLAY_CHANGE_OBSERVER_X11_H
+#ifndef ASH_DISPLAY_DISPLAY_UTIL_X11_H_
+#define ASH_DISPLAY_DISPLAY_UTIL_X11_H_
 
-#include <X11/Xlib.h>
-
-// Xlib.h defines RootWindow.
-#undef RootWindow
+#include <vector>
 
 #include "ash/ash_export.h"
-#include "ash/shell_observer.h"
-#include "base/basictypes.h"
-#include "chromeos/display/output_configurator.h"
+#include "ash/display/display_info.h"
+
+struct _XRRScreenResources;
+typedef _XRRScreenResources XRRScreenResources;
+struct _XRROutputInfo;
+typedef _XRROutputInfo XRROutputInfo;
 
 namespace ash {
 namespace internal {
-
-// An object that observes changes in display configuration and
-// update DisplayManagers.
-class DisplayChangeObserverX11
-    : public chromeos::OutputConfigurator::StateController,
-      public chromeos::OutputConfigurator::Observer,
-      public ShellObserver {
- public:
-  DisplayChangeObserverX11();
-  virtual ~DisplayChangeObserverX11();
-
-  // chromeos::OutputConfigurator::StateController overrides:
-  virtual chromeos::OutputState GetStateForDisplayIds(
-      const std::vector<int64>& outputs) const OVERRIDE;
-
-  // Overriden from chromeos::OutputConfigurator::Observer:
-  virtual void OnDisplayModeChanged() OVERRIDE;
-
-  // Overriden from ShellObserver:
-  virtual void OnAppTerminating() OVERRIDE;
-
- private:
-  Display* xdisplay_;
-
-  ::Window x_root_window_;
-
-  int xrandr_event_base_;
-
-  DISALLOW_COPY_AND_ASSIGN(DisplayChangeObserverX11);
-};
+struct Resolution;
 
 // Returns true if the size info in the output_info isn't valid
 // and should be ignored. This is exposed for testing.
 // |mm_width| and |mm_height| are given in millimeters.
 ASH_EXPORT bool ShouldIgnoreSize(unsigned long mm_width,
                                  unsigned long mm_height);
 
+// Returns the resolution list.
+ASH_EXPORT std::vector<Resolution> GetResolutionList(
+    XRRScreenResources* screen_resources,
+    XRROutputInfo* output_info);
+
 }  // namespace internal
 }  // namespace ash
 
-#endif  // ASH_DISPLAY_AURA_DISPLAY_CHANGE_OBSERVER_X11_H
+#endif  // ASH_DISPLAY_DISPLAY_UTIL_X11_H_