Listen OnDisplayMetricsChanged on lock screen

chrome/browser/chromeos/login/lock/webui_screen_locker.cc

Index: chrome/browser/chromeos/login/lock/webui_screen_locker.cc
diff --git a/chrome/browser/chromeos/login/lock/webui_screen_locker.cc b/chrome/browser/chromeos/login/lock/webui_screen_locker.cc
index da01b7d59ef02b9b3a21bbd19c7d47706938da03..5bf37a08231a264ea7804847731671bc751f9c02 100644
--- a/chrome/browser/chromeos/login/lock/webui_screen_locker.cc
+++ b/chrome/browser/chromeos/login/lock/webui_screen_locker.cc
@@ -68,6 +68,7 @@ WebUIScreenLocker::WebUIScreenLocker(ScreenLocker* screen_locker)
   set_should_emit_login_prompt_visible(false);
   ash::Shell::GetInstance()->lock_state_controller()->AddObserver(this);
   ash::Shell::GetInstance()->delegate()->AddVirtualKeyboardStateObserver(this);
+  ash::Shell::GetScreen()->AddObserver(this);
   DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
 
   if (keyboard::KeyboardController::GetInstance()) {
@@ -155,6 +156,7 @@ void WebUIScreenLocker::FocusUserPod() {
 
 WebUIScreenLocker::~WebUIScreenLocker() {
   DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
+  ash::Shell::GetScreen()->RemoveObserver(this);
   ash::Shell::GetInstance()->
       lock_state_controller()->RemoveObserver(this);
 
@@ -368,4 +370,29 @@ void WebUIScreenLocker::OnKeyboardBoundsChanging(
   keyboard_bounds_ = new_bounds;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// gfx::DisplayObserver implementation:
+
+void WebUIScreenLocker::OnDisplayAdded(const gfx::Display& new_display) {
+}
+
+void WebUIScreenLocker::OnDisplayRemoved(const gfx::Display& old_display) {
+}
+
+void WebUIScreenLocker::OnDisplayMetricsChanged(const gfx::Display& display,
+                                                uint32_t changed_metrics) {
+  gfx::Display primary_display =
+      gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
+  if (display.id() != primary_display.id() ||
+      !(changed_metrics & DISPLAY_METRIC_BOUNDS)) {
+    return;
+  }
+
+  if (GetOobeUI()) {
+    const gfx::Size& size = primary_display.size();
+    GetOobeUI()->GetCoreOobeActor()->SetClientAreaSize(size.width(),
+                                                       size.height());
+  }
+}
+
 }  // namespace chromeos