Allow storing display preferences per device.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 3caf2fea13d7ed7b6a9ad72cb777cfdea9b51821..d606d32c79ceffc565f54f1029a9253f9ec658d9 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -185,7 +185,7 @@ Shell::Shell(ShellDelegate* delegate)
       delegate_(delegate),
 #if defined(OS_CHROMEOS)
       output_configurator_(new chromeos::OutputConfigurator(
-          internal::DisplayController::IsExtendedDesktopEnabled())),
+          DisplayController::IsExtendedDesktopEnabled())),
       output_configurator_animation_(
           new internal::OutputConfiguratorAnimation()),
 #endif  // defined(OS_CHROMEOS)
@@ -372,7 +372,7 @@ void Shell::Init() {
       new internal::ActivationController(focus_manager_.get()));
 
   screen_position_controller_.reset(new internal::ScreenPositionController);
-  display_controller_.reset(new internal::DisplayController);
+  display_controller_.reset(new DisplayController);
   display_controller_->InitPrimaryDisplay();
   aura::RootWindow* root_window = display_controller_->GetPrimaryRootWindow();
   active_root_window_ = root_window;
@@ -422,7 +422,7 @@ void Shell::Init() {
     AddEnvEventFilter(touch_observer_hud_.get());
   }
 
-  if (internal::DisplayController::IsExtendedDesktopEnabled()) {
+  if (DisplayController::IsExtendedDesktopEnabled()) {
     mouse_cursor_filter_.reset(
         new internal::MouseCursorEventFilter(display_controller_.get()));
     AddEnvEventFilter(mouse_cursor_filter_.get());
@@ -669,7 +669,7 @@ int Shell::GetGridSize() const {
 
 void Shell::InitRootWindowForSecondaryDisplay(aura::RootWindow* root) {
   root->set_focus_manager(focus_manager_.get());
-  if (internal::DisplayController::IsExtendedDesktopEnabled()) {
+  if (DisplayController::IsExtendedDesktopEnabled()) {
     internal::RootWindowController* controller =
         new internal::RootWindowController(root);
     controller->CreateContainers();