Make Page Visibility API work when the browser window is visible or not

ui/aura/window_unittest.cc

 // Copyright (c) 2012 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 "ui/aura/window.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 1799 matching lines @@
     }
     transform_notifications_.clear();
     return result;
   }
 
  private:
   void OnWindowAdded(Window* new_window) override { added_count_++; }
 
   void OnWillRemoveWindow(Window* window) override { removed_count_++; }
 
-  void OnWindowVisibilityChanged(Window* window, bool visible) override {
+  void OnWindowVisibilityChanged(Window* window, bool visible,
+      bool content_visible) override {
     if (!visibility_info_) {
       visibility_info_.reset(new VisibilityInfo);
       visibility_info_->changed_count = 0;
     }
     visibility_info_->window_visible = window->IsVisible();
     visibility_info_->visible_param = visible;
     visibility_info_->changed_count++;
   }
 
   void OnWindowDestroyed(Window* window) override {
@@ skipping 1759 matching lines @@
 
   EXPECT_TRUE(animator.get());
   EXPECT_FALSE(animator->is_animating());
   EXPECT_TRUE(observer.animation_completed());
   EXPECT_FALSE(observer.animation_aborted());
   animator->RemoveObserver(&observer);
 }
 
 }  // namespace test
 }  // namespace aura