Creates notifications for display resolution change.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 1bade434dd44a35b45a7547c5bd7dd0329067b33..b64c26f9e49c79cccadc14e1c467b24af7afb60b 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -17,6 +17,7 @@
 #include "ash/display/display_manager.h"
 #include "ash/display/event_transformation_handler.h"
 #include "ash/display/mouse_cursor_event_filter.h"
+#include "ash/display/resolution_notification_controller.h"
 #include "ash/display/screen_position_controller.h"
 #include "ash/drag_drop/drag_drop_controller.h"
 #include "ash/focus_cycler.h"
@@ -312,6 +313,8 @@ Shell::~Shell() {
   lock_state_controller_.reset();
   mru_window_tracker_.reset();
 
+  resolution_notification_controller_.reset();
+
   // This also deletes all RootWindows. Note that we invoke Shutdown() on
   // DisplayController before resetting |display_controller_|, since destruction
   // of its owned RootWindowControllers relies on the value.
@@ -505,6 +508,9 @@ void Shell::Init() {
   aura::RootWindow* root_window = display_controller_->GetPrimaryRootWindow();
   target_root_window_ = root_window;
 
+  resolution_notification_controller_.reset(
+      new internal::ResolutionNotificationController);
+
   cursor_manager_.SetDisplay(DisplayController::GetPrimaryDisplay());
 
 #if !defined(OS_MACOSX)