Add OnDisplayMetricsChanged in DisplayObserver.

ash/wm/maximize_mode/maximize_mode_window_manager.cc

 // Copyright 2014 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/wm/maximize_mode/maximize_mode_window_manager.h"
 
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/maximize_mode/maximize_mode_window_state.h"
@@ skipping 97 matching lines @@
   if (!IsContainerWindow(window))
     return;
   // Reposition all non maximizeable windows.
   for (WindowToState::iterator it = window_state_map_.begin();
        it != window_state_map_.end();
        ++it) {
     it->second->UpdateWindowPosition(wm::GetWindowState(it->first), false);
   }
 }
 
-void MaximizeModeWindowManager::OnDisplayBoundsChanged(
-    const gfx::Display& display) {
-  // Nothing to do here.
-}
-
 void MaximizeModeWindowManager::OnDisplayAdded(const gfx::Display& display) {
   DisplayConfigurationChanged();
 }
 
 void MaximizeModeWindowManager::OnDisplayRemoved(const gfx::Display& display) {
   DisplayConfigurationChanged();
 }
 
+void MaximizeModeWindowManager::OnDisplayMetricsChanged(
+    const gfx::Display&,
+    DisplayObserver::DisplayMetrics) {
+  // Nothing to do here.
+}
+
 void MaximizeModeWindowManager::OnTouchEvent(ui::TouchEvent* event) {
   if (event->type() != ui::ET_TOUCH_PRESSED)
     return;
 
   // Find the active window (from the primary screen) to un-fullscreen.
   aura::Window* window = wm::GetActiveWindow();
   if (!window)
     return;
 
   wm::WindowState* window_state = wm::GetWindowState(window);
@@ skipping 126 matching lines @@
     RootWindowController* controller = *iter;
     aura::Window* container = Shell::GetContainer(
         controller->GetRootWindow(), kShellWindowId_DefaultContainer);
     controller->workspace_controller()->SetMaximizeBackdropDelegate(
         scoped_ptr<WorkspaceLayoutManagerDelegate>(
             enable ? new WorkspaceBackdropDelegate(container) : NULL));
   }
 }
 
 }  // namespace ash