Generalize support for per-display shelf prefs.

chrome/browser/ui/ash/multi_user/user_switch_animator_chromeos.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 "chrome/browser/ui/ash/multi_user/user_switch_animator_chromeos.h"
 
 #include "ash/desktop_background/user_wallpaper_delegate.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_widget.h"
@@ skipping 208 matching lines @@
       ChromeLauncherController::instance();
   // The shelf animation duration override.
   int duration_override = animation_speed_ms_;
   // Handle the shelf order of items. This is done once the old user is hidden.
   if (animation_step == ANIMATION_STEP_SHOW_NEW_USER) {
     // Some unit tests have no ChromeLauncherController.
     if (chrome_launcher_controller)
       chrome_launcher_controller->ActiveUserChanged(
           new_account_id_.GetUserEmail());
     // Hide the black rectangle on top of each shelf again.
-    aura::Window::Windows root_windows = ash::Shell::GetAllRootWindows();
-    for (aura::Window::Windows::const_iterator iter = root_windows.begin();
-         iter != root_windows.end(); ++iter) {
-      ash::ShelfWidget* shelf =
-          ash::RootWindowController::ForWindow(*iter)->shelf();
+    for (aura::Window* window : ash::Shell::GetAllRootWindows()) {
+      ash::ShelfWidget* shelf = ash::Shelf::ForWindow(window)->shelf_widget();
       shelf->HideShelfBehindBlackBar(false, duration_override);
     }
     // We kicked off the shelf animation above and the override can be
     // removed.
     duration_override = 0;
   }
 
   if (!animation_speed_ms_ || animation_step == ANIMATION_STEP_FINALIZE)
     return;
 
   // Note: The animation duration override will be set before the old user gets
   // hidden and reset after the animations for the new user got kicked off.
   ash::Shell::RootWindowControllerList controller =
       ash::Shell::GetInstance()->GetAllRootWindowControllers();
   for (ash::Shell::RootWindowControllerList::iterator iter = controller.begin();
        iter != controller.end(); ++iter) {
     (*iter)->GetShelfLayoutManager()->SetAnimationDurationOverride(
         duration_override);
   }
 
   if (animation_step != ANIMATION_STEP_HIDE_OLD_USER)
     return;
 
   // For each root window hide the shelf.
-  aura::Window::Windows root_windows = ash::Shell::GetAllRootWindows();
-
-  for (aura::Window::Windows::const_iterator iter = root_windows.begin();
-       iter != root_windows.end(); ++iter) {
+  for (aura::Window* window : ash::Shell::GetAllRootWindows()) {
     // Hiding the shelf will cause a resize on a maximized window.
     // If the shelf is then shown for the following user in the same location,
     // the window gets resized again. Since each resize can cause a considerable
     // CPU usage and therefore effect jank, we should avoid hiding the shelf if
     // the start and end location are the same and cover the shelf instead with
     // a black rectangle on top.
-    if (GetScreenCover(*iter) != NO_USER_COVERS_SCREEN &&
+    ash::Shelf* shelf = ash::Shelf::ForWindow(window);
+    if (GetScreenCover(window) != NO_USER_COVERS_SCREEN &&
         (!chrome_launcher_controller ||
          !chrome_launcher_controller->ShelfBoundsChangesProbablyWithUser(
-             *iter, new_account_id_.GetUserEmail()))) {
-      ash::ShelfWidget* shelf =
-          ash::RootWindowController::ForWindow(*iter)->shelf();
-      shelf->HideShelfBehindBlackBar(true, duration_override);
+             shelf, new_account_id_.GetUserEmail()))) {
+      shelf->shelf_widget()->HideShelfBehindBlackBar(true, duration_override);
     } else {
       // This shelf change is only part of the animation and will be updated by
       // ChromeLauncherController::ActiveUserChanged() to the new users value.
       // Note that the user preference will not be changed.
-      ash::Shell::GetInstance()->SetShelfAutoHideBehavior(
-          ash::SHELF_AUTO_HIDE_ALWAYS_HIDDEN, *iter);
+      shelf->SetAutoHideBehavior(ash::SHELF_AUTO_HIDE_ALWAYS_HIDDEN);
     }
   }
 }
 
 void UserSwitchAnimatorChromeOS::TransitionWindows(
     AnimationStep animation_step) {
   // Disable the window position manager and the MRU window tracker temporarily.
   UserChangeActionDisabler disabler;
 
   // Animation duration.
@@ skipping 147 matching lines @@
         if (itr != window_to_entry_map.end()) {
           windows_by_account_id_[itr->second->show_for_user()].push_back(
               child_window);
         }
       }
     }
   }
 }
 
 }  // namespace chrome