Enable display rotation, magnifier in unified desktop mode

ash/display/display_manager.cc

 // Copyright (c) 2012 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/display_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <set>
 #include <string>
@@ skipping 999 matching lines @@
   return software_mirroring_enabled();
 }
 #endif
 
 void DisplayManager::SetMultiDisplayMode(MultiDisplayMode mode) {
   multi_display_mode_ = mode;
   mirroring_display_id_ = gfx::Display::kInvalidDisplayID;
   software_mirroring_display_list_.clear();
 }
 
+void DisplayManager::SetDefaultMultiDisplayMode(MultiDisplayMode mode) {
+  // TODO(oshima): Remove this constrain.
+  DCHECK_EQ(default_multi_display_mode_, EXTENDED);
+  DCHECK_EQ(mode, UNIFIED);
+  default_multi_display_mode_ = mode;
+}
+
 bool DisplayManager::UpdateDisplayBounds(int64 display_id,
                                          const gfx::Rect& new_bounds) {
   if (change_display_upon_host_resize_) {
     display_info_[display_id].SetBounds(new_bounds);
     // Don't notify observers if the mirrored window has changed.
     if (software_mirroring_enabled() && mirroring_display_id_ == display_id)
       return false;
     gfx::Display* display = FindDisplayForId(display_id);
     display->SetSize(display_info_[display_id].size_in_pixel());
     screen_->NotifyMetricsChanged(*display,
@@ skipping 277 matching lines @@
       gfx::Rect(new_secondary_origin, secondary_bounds.size()));
   secondary_display->UpdateWorkAreaFromInsets(insets);
 }
 
 void DisplayManager::RunPendingTasksForTest() {
   if (!software_mirroring_display_list_.empty())
     base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace ash