arc: Implement proper Arc window activation for task moving to front.

chrome/browser/ui/ash/launcher/arc_app_window_launcher_controller.cc

 // Copyright 2016 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/launcher/arc_app_window_launcher_controller.h"
 
 #include <string>
 
 #include "ash/common/shelf/shelf_delegate.h"
 #include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
 #include "ash/common/wm/window_state.h"
@@ skipping 445 matching lines @@
     // TODO(reveman): Figure out how to support fullscreen in interleaved
     // window mode.
     // if (new_active_app_it->second->widget()) {
     //   new_active_app_it->second->widget()->SetFullscreen(
     //       new_active_app_it->second->fullscreen_mode() ==
     //       FullScreenMode::ACTIVE);
     // }
   }
 }
 
+void ArcAppWindowLauncherController::OnTaskMovedToFront(int32_t task_id) {
+  TaskIdToAppWindow::const_iterator app_it =
+      task_id_to_app_window_.find(task_id);
+  if (app_it == task_id_to_app_window_.end())
+    return;
+  if (app_it->second->IsActive())
+    return;
+  app_it->second->Activate();
+}
+
 void ArcAppWindowLauncherController::OnTaskOrientationLockRequested(
     int32_t task_id,
     const arc::mojom::OrientationLock orientation_lock) {
   // Don't save to AppInfo because this is requested in runtime.
   TaskIdToAppWindow::iterator app_it = task_id_to_app_window_.find(task_id);
   if (app_it == task_id_to_app_window_.end())
     return;
   AppWindow* app_window = app_it->second.get();
   app_window->set_requested_orientation_lock(orientation_lock);
 
@@ skipping 124 matching lines @@
   if (orientation_lock == arc::mojom::OrientationLock::CURRENT) {
     // Resolve the orientation when it first resolved.
     orientation_lock = GetCurrentOrientation();
     app_window->set_requested_orientation_lock(orientation_lock);
   }
 
   ash::Shell* shell = ash::Shell::GetInstance();
   shell->screen_orientation_controller()->LockOrientationForWindow(
       window, BlinkOrientationLockFromMojom(orientation_lock));
 }