Reload wallpaper when display configuration changes.

BUG=285365,239849
R=bshe@chromium.org

Review URL: https://codereview.chromium.org/24499002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225386 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 242 insertions, 69 deletions

diff --git a/ash/ash.gyp b/ash/ash.gyp
index 72fa429..895318d 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -76,6 +76,8 @@
         'caps_lock_delegate_stub.h',
         'debug.cc',
         'debug.h',
+        'default_user_wallpaper_delegate.cc',
+        'default_user_wallpaper_delegate.h',
         'desktop_background/desktop_background_controller.cc',
         'desktop_background/desktop_background_controller.h',
         'desktop_background/desktop_background_controller_observer.h',
@@ -608,6 +610,8 @@
         'test/shell_test_api.h',
         'test/test_activation_delegate.cc',
         'test/test_activation_delegate.h',
+        'test/test_user_wallpaper_delegate.cc',
+        'test/test_user_wallpaper_delegate.h',
         'test/test_launcher_delegate.cc',
         'test/test_launcher_delegate.h',
         'test/test_session_state_delegate.cc',
diff --git a/ash/default_user_wallpaper_delegate.cc b/ash/default_user_wallpaper_delegate.cc
new file mode 100644
index 0000000..168fc9d
--- /dev/null
+++ b/ash/default_user_wallpaper_delegate.cc
@@ -0,0 +1,41 @@
+// Copyright 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 "ash/default_user_wallpaper_delegate.h"
+
+#include "ash/desktop_background/desktop_background_controller.h"
+#include "ash/shell.h"
+
+namespace ash {
+
+int DefaultUserWallpaperDelegate::GetAnimationType() {
+  return views::corewm::WINDOW_VISIBILITY_ANIMATION_TYPE_FADE;
+}
+
+bool DefaultUserWallpaperDelegate::ShouldShowInitialAnimation() {
+  return false;
+}
+
+void DefaultUserWallpaperDelegate::UpdateWallpaper() {
+}
+
+void DefaultUserWallpaperDelegate::InitializeWallpaper() {
+  ash::Shell::GetInstance()->desktop_background_controller()->
+      CreateEmptyWallpaper();
+}
+
+void DefaultUserWallpaperDelegate::OpenSetWallpaperPage() {
+}
+
+bool DefaultUserWallpaperDelegate::CanOpenSetWallpaperPage() {
+  return false;
+}
+
+void DefaultUserWallpaperDelegate::OnWallpaperAnimationFinished() {
+}
+
+void DefaultUserWallpaperDelegate::OnWallpaperBootAnimationFinished() {
+}
+
+}  // namespace ash
diff --git a/ash/default_user_wallpaper_delegate.h b/ash/default_user_wallpaper_delegate.h
new file mode 100644
index 0000000..2e22e30
--- /dev/null
+++ b/ash/default_user_wallpaper_delegate.h
@@ -0,0 +1,36 @@
+// Copyright 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.
+
+#ifndef ASH_DEFAULT_USER_WALLPAPER_DELEGATE_H_
+#define ASH_DEFAULT_USER_WALLPAPER_DELEGATE_H_
+
+#include "ash/ash_export.h"
+#include "ash/desktop_background/user_wallpaper_delegate.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+
+namespace ash {
+
+class ASH_EXPORT DefaultUserWallpaperDelegate : public UserWallpaperDelegate {
+ public:
+  DefaultUserWallpaperDelegate() {}
+  virtual ~DefaultUserWallpaperDelegate() {}
+
+  // UserWallpaperDelegate overrides:
+  virtual int GetAnimationType() OVERRIDE;
+  virtual bool ShouldShowInitialAnimation() OVERRIDE;
+  virtual void UpdateWallpaper() OVERRIDE;
+  virtual void InitializeWallpaper() OVERRIDE;
+  virtual void OpenSetWallpaperPage() OVERRIDE;
+  virtual bool CanOpenSetWallpaperPage() OVERRIDE;
+  virtual void OnWallpaperAnimationFinished() OVERRIDE;
+  virtual void OnWallpaperBootAnimationFinished() OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DefaultUserWallpaperDelegate);
+};
+
+}  // namespace ash
+
+#endif  // ASH_DEFAULT_USER_WALLPAPER_DELEGATE_H_
diff --git a/ash/desktop_background/desktop_background_controller.cc b/ash/desktop_background/desktop_background_controller.cc
index b8fef38..8cdd72e 100644
--- a/ash/desktop_background/desktop_background_controller.cc
+++ b/ash/desktop_background/desktop_background_controller.cc
@@ -39,6 +39,10 @@ using content::BrowserThread;
 namespace ash {
 namespace {
 
+// How long to wait reloading the wallpaper after the max display has
+// changed?
+const int kWallpaperReloadDelayMs = 2000;
+
 const SkColor kTransparentColor = SkColorSetARGB(0x00, 0x00, 0x00, 0x00);
 
 internal::RootWindowLayoutManager* GetRootWindowLayoutManager(
@@ -161,11 +165,14 @@ DesktopBackgroundController::DesktopBackgroundController()
       locked_(false),
       desktop_background_mode_(BACKGROUND_NONE),
       current_default_wallpaper_resource_id_(-1),
-      weak_ptr_factory_(this) {
+      weak_ptr_factory_(this),
+      wallpaper_reload_delay_(kWallpaperReloadDelayMs) {
+  Shell::GetInstance()->display_controller()->AddObserver(this);
 }
 
 DesktopBackgroundController::~DesktopBackgroundController() {
   CancelPendingWallpaperOperation();
+  Shell::GetInstance()->display_controller()->RemoveObserver(this);
 }
 
 gfx::ImageSkia DesktopBackgroundController::GetWallpaper() const {
@@ -195,23 +202,13 @@ void DesktopBackgroundController::OnRootWindowAdded(
   // The background hasn't been set yet.
   if (desktop_background_mode_ == BACKGROUND_NONE)
     return;
-
+  gfx::Size max_display_size = GetMaxDisplaySizeInNative();
   // Handle resolution change for "built-in" images.
   if (BACKGROUND_IMAGE == desktop_background_mode_ &&
-      current_wallpaper_.get()) {
-    gfx::Size root_window_size = root_window->GetHostSize();
-    int width = current_wallpaper_->wallpaper_image().width();
-    int height = current_wallpaper_->wallpaper_image().height();
-    // Reloads wallpaper if current wallpaper is smaller than the new added root
-    // window.
-    if (width < root_window_size.width() ||
-        height < root_window_size.height()) {
-      current_wallpaper_.reset(NULL);
-      current_default_wallpaper_path_ = base::FilePath();
-      current_default_wallpaper_resource_id_ = -1;
-      ash::Shell::GetInstance()->user_wallpaper_delegate()->
-          UpdateWallpaper();
-    }
+      current_wallpaper_.get() &&
+      current_max_display_size_ != max_display_size) {
+    current_max_display_size_ = max_display_size;
+    UpdateWallpaper();
   }
 
   InstallDesktopController(root_window);
@@ -310,6 +307,18 @@ bool DesktopBackgroundController::MoveDesktopToUnlockedContainer() {
                                    GetBackgroundContainerId(false));
 }
 
+void DesktopBackgroundController::OnDisplayConfigurationChanged() {
+  gfx::Size max_display_size = GetMaxDisplaySizeInNative();
+  if (current_max_display_size_ != max_display_size) {
+    current_max_display_size_ = max_display_size;
+    timer_.Stop();
+    timer_.Start(FROM_HERE,
+                 base::TimeDelta::FromMilliseconds(wallpaper_reload_delay_),
+                 this,
+                 &DesktopBackgroundController::UpdateWallpaper);
+  }
+}
+
 bool DesktopBackgroundController::DefaultWallpaperIsAlreadyLoadingOrLoaded(
     const base::FilePath& image_file, int image_resource_id) const {
   return (wallpaper_loader_.get() &&
@@ -375,6 +384,7 @@ void DesktopBackgroundController::InstallDesktopControllerForAllWindows() {
        iter != root_windows.end(); ++iter) {
     InstallDesktopController(*iter);
   }
+  current_max_display_size_ = GetMaxDisplaySizeInNative();
 }
 
 bool DesktopBackgroundController::ReparentBackgroundWidgets(int src_container,
@@ -420,6 +430,14 @@ int DesktopBackgroundController::GetBackgroundContainerId(bool locked) {
                   internal::kShellWindowId_DesktopBackgroundContainer;
 }
 
+void DesktopBackgroundController::UpdateWallpaper() {
+  current_wallpaper_.reset(NULL);
+  current_default_wallpaper_path_ = base::FilePath();
+  current_default_wallpaper_resource_id_ = -1;
+  ash::Shell::GetInstance()->user_wallpaper_delegate()->
+      UpdateWallpaper();
+}
+
 // static
 gfx::Size DesktopBackgroundController::GetMaxDisplaySizeInNative() {
   int width = 0;
diff --git a/ash/desktop_background/desktop_background_controller.h b/ash/desktop_background/desktop_background_controller.h
index 4955d20..fdcd748 100644
--- a/ash/desktop_background/desktop_background_controller.h
+++ b/ash/desktop_background/desktop_background_controller.h
@@ -6,12 +6,14 @@
 #define ASH_DESKTOP_BACKGROUND_DESKTOP_BACKGROUND_CONTROLLER_H_
 
 #include "ash/ash_export.h"
+#include "ash/display/display_controller.h"
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "base/timer/timer.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
 #include "ui/gfx/image/image_skia.h"
@@ -65,7 +67,8 @@ class WallpaperResizer;
 
 // Loads selected desktop wallpaper from file system asynchronously and updates
 // background layer if loaded successfully.
-class ASH_EXPORT DesktopBackgroundController {
+class ASH_EXPORT DesktopBackgroundController
+    : public DisplayController::Observer {
  public:
   enum BackgroundMode {
     BACKGROUND_NONE,
@@ -128,6 +131,9 @@ class ASH_EXPORT DesktopBackgroundController {
   // Returns true if the desktop moved.
   bool MoveDesktopToUnlockedContainer();
 
+  // Overrides DisplayController::Observer:
+  virtual void OnDisplayConfigurationChanged() OVERRIDE;
+
  private:
   friend class DesktopBackgroundControllerTest;
   FRIEND_TEST_ALL_PREFIXES(DesktopBackgroundControllerTest, GetMaxDisplaySize);
@@ -170,6 +176,13 @@ class ASH_EXPORT DesktopBackgroundController {
   // Send notification that background animation finished.
   void NotifyAnimationFinished();
 
+  // Reload the wallpaper.
+  void UpdateWallpaper();
+
+  void set_wallpaper_reload_delay_for_test(bool value) {
+    wallpaper_reload_delay_ = value;
+  }
+
   // Returns the maximum size of all displays combined in native
   // resolutions.  Note that this isn't the bounds of the display who
   // has maximum resolutions. Instead, this returns the size of the
@@ -197,10 +210,16 @@ class ASH_EXPORT DesktopBackgroundController {
   base::FilePath current_default_wallpaper_path_;
   int current_default_wallpaper_resource_id_;
 
+  gfx::Size current_max_display_size_;
+
   scoped_refptr<WallpaperLoader> wallpaper_loader_;
 
   base::WeakPtrFactory<DesktopBackgroundController> weak_ptr_factory_;
 
+  base::OneShotTimer<DesktopBackgroundController> timer_;
+
+  int wallpaper_reload_delay_;
+
   DISALLOW_COPY_AND_ASSIGN(DesktopBackgroundController);
 };
 
diff --git a/ash/desktop_background/desktop_background_controller_unittest.cc b/ash/desktop_background/desktop_background_controller_unittest.cc
index c29c96d..5e4a2ea 100644
--- a/ash/desktop_background/desktop_background_controller_unittest.cc
+++ b/ash/desktop_background/desktop_background_controller_unittest.cc
@@ -15,6 +15,7 @@
 #include "ash/shell_window_ids.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/display_manager_test_api.h"
+#include "ash/test/test_user_wallpaper_delegate.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ -112,6 +113,9 @@ class DesktopBackgroundControllerTest : public test::AshTestBase {
     root_window_controller->SetWallpaperController(NULL);
     root_window_controller->SetAnimatingWallpaperController(NULL);
     controller_ = Shell::GetInstance()->desktop_background_controller();
+    wallpaper_delegate_ = static_cast<test::TestUserWallpaperDelegate*>(
+        Shell::GetInstance()->user_wallpaper_delegate());
+    controller_->set_wallpaper_reload_delay_for_test(0);
   }
 
  protected:
@@ -254,6 +258,8 @@ class DesktopBackgroundControllerTest : public test::AshTestBase {
 
   DesktopBackgroundController* controller_;  // Not owned.
 
+  test::TestUserWallpaperDelegate* wallpaper_delegate_;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(DesktopBackgroundControllerTest);
 };
@@ -415,13 +421,9 @@ TEST_F(DesktopBackgroundControllerTest, ChangeWallpaperQuick) {
             root_window_controller->wallpaper_controller());
 }
 
-TEST_F(DesktopBackgroundControllerTest, GetAppropriateResolution) {
-  // TODO(derat|oshima|bshe): Configuring desktops seems busted on Win8,
-  // even when just a single display is being used -- the small wallpaper
-  // is used instead of the large one. Track down the cause of the problem
-  // and only use a SupportsMultipleDisplays() clause for the dual-display
-  // code below.
-  if (!SupportsMultipleDisplays())
+TEST_F(DesktopBackgroundControllerTest, DisplayChange) {
+  // TODO(derat|oshima|bshe): Host windows can't be resized on Win8.
+  if (!SupportsHostWindowResize())
     return;
 
   test::DisplayManagerTestApi display_manager_test_api(
@@ -431,36 +433,75 @@ TEST_F(DesktopBackgroundControllerTest, GetAppropriateResolution) {
   // equal to kSmallWallpaperMaxWidth by kSmallWallpaperMaxHeight, even if
   // multiple displays are connected.
   display_manager_test_api.UpdateDisplay("800x600");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_SMALL,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(0,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
+
   display_manager_test_api.UpdateDisplay("800x600,800x600");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_SMALL,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(0,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
+
   display_manager_test_api.UpdateDisplay("1366x800");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_SMALL,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(1,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
 
   // At larger sizes, large wallpapers should be used.
   display_manager_test_api.UpdateDisplay("1367x800");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_LARGE,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(1,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
+
   display_manager_test_api.UpdateDisplay("1367x801");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_LARGE,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(1,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
+
   display_manager_test_api.UpdateDisplay("2560x1700");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_LARGE,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(1,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
 
   // Rotated smaller screen may use larger image.
   display_manager_test_api.UpdateDisplay("800x600/r");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_SMALL,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(1,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
+
   display_manager_test_api.UpdateDisplay("800x600/r,800x600");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_SMALL,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(1,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
   display_manager_test_api.UpdateDisplay("1366x800/r");
+  RunAllPendingInMessageLoop();
   EXPECT_EQ(WALLPAPER_RESOLUTION_LARGE,
             controller_->GetAppropriateResolution());
+  EXPECT_EQ(1,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
+
+  // Max display size didn't chagne.
+  display_manager_test_api.UpdateDisplay("900x800/r,400x1366");
+  RunAllPendingInMessageLoop();
+  EXPECT_EQ(0,
+            wallpaper_delegate_->GetUpdateWallpaperCountAndReset());
+
 }
 
 // Test that DesktopBackgroundController loads the appropriate wallpaper
diff --git a/ash/shell.cc b/ash/shell.cc
index 3606c5d..8ee32d7 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -128,47 +128,6 @@ namespace {
 using aura::Window;
 using views::Widget;
 
-// This dummy class is used for shell unit tests. We dont have chrome delegate
-// in these tests.
-class DummyUserWallpaperDelegate : public UserWallpaperDelegate {
- public:
-  DummyUserWallpaperDelegate() {}
-
-  virtual ~DummyUserWallpaperDelegate() {}
-
-  virtual int GetAnimationType() OVERRIDE {
-    return views::corewm::WINDOW_VISIBILITY_ANIMATION_TYPE_FADE;
-  }
-
-  virtual bool ShouldShowInitialAnimation() OVERRIDE {
-    return false;
-  }
-
-  virtual void UpdateWallpaper() OVERRIDE {
-  }
-
-  virtual void InitializeWallpaper() OVERRIDE {
-    ash::Shell::GetInstance()->desktop_background_controller()->
-        CreateEmptyWallpaper();
-  }
-
-  virtual void OpenSetWallpaperPage() OVERRIDE {
-  }
-
-  virtual bool CanOpenSetWallpaperPage() OVERRIDE {
-    return false;
-  }
-
-  virtual void OnWallpaperAnimationFinished() OVERRIDE {
-  }
-
-  virtual void OnWallpaperBootAnimationFinished() OVERRIDE {
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(DummyUserWallpaperDelegate);
-};
-
 // A Corewm VisibilityController subclass that calls the Ash animation routine
 // so we can pick up our extended animations. See ash/wm/window_animations.h.
 class AshVisibilityController : public views::corewm::VisibilityController {
@@ -309,6 +268,7 @@ Shell::~Shell() {
   mru_window_tracker_.reset();
 
   resolution_notification_controller_.reset();
+  desktop_background_controller_.reset();
 
   // This also deletes all RootWindows. Note that we invoke Shutdown() on
   // DisplayController before resetting |display_controller_|, since destruction
@@ -569,8 +529,6 @@ void Shell::Init() {
   // This controller needs to be set before SetupManagedWindowMode.
   desktop_background_controller_.reset(new DesktopBackgroundController());
   user_wallpaper_delegate_.reset(delegate_->CreateUserWallpaperDelegate());
-  if (!user_wallpaper_delegate_)
-    user_wallpaper_delegate_.reset(new DummyUserWallpaperDelegate());
 
   // StatusAreaWidget uses Shell's CapsLockDelegate.
   caps_lock_delegate_.reset(delegate_->CreateCapsLockDelegate());
diff --git a/ash/shell/shell_delegate_impl.cc b/ash/shell/shell_delegate_impl.cc
index eb6839c..fd95202 100644
--- a/ash/shell/shell_delegate_impl.cc
+++ b/ash/shell/shell_delegate_impl.cc
@@ -7,6 +7,7 @@
 #include <limits>
 
 #include "ash/caps_lock_delegate_stub.h"
+#include "ash/default_user_wallpaper_delegate.h"
 #include "ash/host/root_window_host_factory.h"
 #include "ash/keyboard_controller_proxy_stub.h"
 #include "ash/session_state_delegate.h"
@@ -173,7 +174,7 @@ ash::SystemTrayDelegate* ShellDelegateImpl::CreateSystemTrayDelegate() {
 }
 
 ash::UserWallpaperDelegate* ShellDelegateImpl::CreateUserWallpaperDelegate() {
-  return NULL;
+  return new DefaultUserWallpaperDelegate();
 }
 
 ash::CapsLockDelegate* ShellDelegateImpl::CreateCapsLockDelegate() {
diff --git a/ash/test/test_shell_delegate.cc b/ash/test/test_shell_delegate.cc
index 85851eb..7423822 100644
--- a/ash/test/test_shell_delegate.cc
+++ b/ash/test/test_shell_delegate.cc
@@ -15,6 +15,7 @@
 #include "ash/test/test_launcher_delegate.h"
 #include "ash/test/test_session_state_delegate.h"
 #include "ash/test/test_system_tray_delegate.h"
+#include "ash/test/test_user_wallpaper_delegate.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "base/logging.h"
@@ -163,7 +164,7 @@ SystemTrayDelegate* TestShellDelegate::CreateSystemTrayDelegate() {
 }
 
 UserWallpaperDelegate* TestShellDelegate::CreateUserWallpaperDelegate() {
-  return NULL;
+  return new TestUserWallpaperDelegate();
 }
 
 CapsLockDelegate* TestShellDelegate::CreateCapsLockDelegate() {
diff --git a/ash/test/test_user_wallpaper_delegate.cc b/ash/test/test_user_wallpaper_delegate.cc
new file mode 100644
index 0000000..c3eb16e
--- /dev/null
+++ b/ash/test/test_user_wallpaper_delegate.cc
@@ -0,0 +1,22 @@
+// Copyright 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 "ash/test/test_user_wallpaper_delegate.h"
+
+namespace ash {
+namespace test {
+
+void TestUserWallpaperDelegate::UpdateWallpaper() {
+  DefaultUserWallpaperDelegate::UpdateWallpaper();
+  update_wallpaper_count_ ++;
+}
+
+int TestUserWallpaperDelegate::GetUpdateWallpaperCountAndReset() {
+  int count = update_wallpaper_count_;
+  update_wallpaper_count_ = 0;
+  return count;
+}
+
+}  // namespace test
+}  // namespace ash
diff --git a/ash/test/test_user_wallpaper_delegate.h b/ash/test/test_user_wallpaper_delegate.h
new file mode 100644
index 0000000..56842357
--- /dev/null
+++ b/ash/test/test_user_wallpaper_delegate.h
@@ -0,0 +1,32 @@
+// Copyright 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.
+
+#ifndef ASH_TEST_TEST_USER_WALLPAPER_DELEGATE_H_
+#define ASH_TEST_TEST_USER_WALLPAPER_DELEGATE_H_
+
+#include "ash/default_user_wallpaper_delegate.h"
+
+namespace ash {
+namespace test {
+
+class TestUserWallpaperDelegate : public DefaultUserWallpaperDelegate {
+ public:
+  TestUserWallpaperDelegate() : update_wallpaper_count_(0) {}
+  virtual ~TestUserWallpaperDelegate() {}
+
+  // DefaultUserWallpaperDelegate overrides:
+  virtual void UpdateWallpaper() OVERRIDE;
+
+  int GetUpdateWallpaperCountAndReset();
+
+ private:
+  int update_wallpaper_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestUserWallpaperDelegate);
+};
+
+}  // namespace test
+}  // namespace ash
+
+#endif  // ASH_TEST_TEST_USER_WALLPAPER_DELEGATE_H_