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

ui/keyboard/keyboard_controller_unittest.cc

 // Copyright (c) 2013 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/keyboard/keyboard_controller.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 130 matching lines @@
 };
 
 class KeyboardContainerObserver : public aura::WindowObserver {
  public:
   explicit KeyboardContainerObserver(aura::Window* window) : window_(window) {
     window_->AddObserver(this);
   }
   ~KeyboardContainerObserver() override { window_->RemoveObserver(this); }
 
  private:
-  void OnWindowVisibilityChanged(aura::Window* window, bool visible) override {
+  void OnWindowVisibilityChanged(aura::Window* window, bool visible,
+      bool content_visible) override {
     if (!visible)
       base::MessageLoop::current()->Quit();
   }
 
   aura::Window* window_;
 
   DISALLOW_COPY_AND_ASSIGN(KeyboardContainerObserver);
 };
 
 }  // namespace
@@ skipping 431 matching lines @@
   // Before hide animation finishes, show keyboard again.
   ShowKeyboard();
   RunAnimationForLayer(layer);
   EXPECT_TRUE(keyboard_container()->IsVisible());
   EXPECT_TRUE(keyboard_window()->IsVisible());
   EXPECT_EQ(1.0, layer->opacity());
   EXPECT_EQ(gfx::Transform(), layer->transform());
 }
 
 }  // namespace keyboard