Recommit r125950, which was reverted by r125958 due to link failures on win_aura bot.

Aura/Ash split: Move ScreenAura to aura::RootWindowScreen.

What is now aura::RootWindowScreen was tightly bundled with aura::RootWindow. Instead of moving it to ash::ScreenAsh, I renamed it aurea::RootWindowScreen because there's a bunch of unit tests that use RootWindow as if it were the desktop. Screen integration stuff has been moved out of RootWindow (and related observers) and into ash::Shell.

BUG=116458
First Review URL: http://codereview.chromium.org/9616045

Review URL: http://codereview.chromium.org/9696008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@126464 0039d316-1c4b-4281-b951-d872f2087c98

32 files changed, 253 insertions, 83 deletions

diff --git a/ash/ash.gyp b/ash/ash.gyp
index e9fdd49..cda2082 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -99,6 +99,8 @@
         'launcher/view_model.h',
         'launcher/view_model_utils.cc',
         'launcher/view_model_utils.h',
+        'screen_ash.cc',
+        'screen_ash.h',
         'screenshot_delegate.h',
         'shell.cc',
         'shell.h',
diff --git a/ui/aura/screen_aura.cc b/ash/screen_ash.cc
index 27e070e..bbdf9e8 100644
--- a/ui/aura/screen_aura.cc
+++ b/ash/screen_ash.cc
@@ -2,65 +2,66 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ui/aura/screen_aura.h"
+#include "ash/screen_ash.h"
 
 #include "base/logging.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/native_widget_types.h"
 
-namespace aura {
+namespace ash {
 
-ScreenAura::ScreenAura(RootWindow* root_window) : root_window_(root_window) {
+ScreenAsh::ScreenAsh(aura::RootWindow* root_window)
+    : root_window_(root_window) {
 }
 
-ScreenAura::~ScreenAura() {
+ScreenAsh::~ScreenAsh() {
 }
 
-gfx::Point ScreenAura::GetCursorScreenPointImpl() {
+gfx::Point ScreenAsh::GetCursorScreenPointImpl() {
   return root_window_->last_mouse_location();
 }
 
-gfx::Rect ScreenAura::GetMonitorWorkAreaNearestWindowImpl(
+gfx::Rect ScreenAsh::GetMonitorWorkAreaNearestWindowImpl(
     gfx::NativeWindow window) {
   return GetWorkAreaBounds();
 }
 
-gfx::Rect ScreenAura::GetMonitorAreaNearestWindowImpl(
+gfx::Rect ScreenAsh::GetMonitorAreaNearestWindowImpl(
     gfx::NativeWindow window) {
   return GetBounds();
 }
 
-gfx::Rect ScreenAura::GetMonitorWorkAreaNearestPointImpl(
+gfx::Rect ScreenAsh::GetMonitorWorkAreaNearestPointImpl(
     const gfx::Point& point) {
   return GetWorkAreaBounds();
 }
 
-gfx::Rect ScreenAura::GetMonitorAreaNearestPointImpl(const gfx::Point& point) {
+gfx::Rect ScreenAsh::GetMonitorAreaNearestPointImpl(const gfx::Point& point) {
   return GetBounds();
 }
 
-gfx::NativeWindow ScreenAura::GetWindowAtCursorScreenPointImpl() {
+gfx::NativeWindow ScreenAsh::GetWindowAtCursorScreenPointImpl() {
   const gfx::Point point = GetCursorScreenPoint();
   return root_window_->GetTopWindowContainingPoint(point);
 }
 
-gfx::Rect ScreenAura::GetBounds() {
+gfx::Rect ScreenAsh::GetBounds() {
   return gfx::Rect(root_window_->bounds().size());
 }
 
-gfx::Rect ScreenAura::GetWorkAreaBounds() {
+gfx::Rect ScreenAsh::GetWorkAreaBounds() {
   gfx::Rect bounds(GetBounds());
   bounds.Inset(work_area_insets_);
   return bounds;
 }
 
-gfx::Size ScreenAura::GetPrimaryMonitorSizeImpl() {
+gfx::Size ScreenAsh::GetPrimaryMonitorSizeImpl() {
   return GetMonitorWorkAreaNearestPoint(gfx::Point()).size();
 }
 
-int ScreenAura::GetNumMonitorsImpl() {
+int ScreenAsh::GetNumMonitorsImpl() {
   return 1;
 }
 
-}  // namespace aura
+}  // namespace ash
diff --git a/ui/aura/screen_aura.h b/ash/screen_ash.h
index ee1540d..deaa76f 100644
--- a/ui/aura/screen_aura.h
+++ b/ash/screen_ash.h
@@ -1,26 +1,28 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
-#ifndef UI_AURA_SCREEN_AURA_H_
-#define UI_AURA_SCREEN_AURA_H_
+#ifndef ASH_SCREEN_ASH_H_
+#define ASH_SCREEN_ASH_H_
 #pragma once
 
 #include "base/compiler_specific.h"
-#include "ui/aura/aura_export.h"
+#include "ash/ash_export.h"
 #include "ui/gfx/insets.h"
 #include "ui/gfx/screen.h"
 
 namespace aura {
-
 class RootWindow;
+}
+
+namespace ash {
 
 // Aura implementation of gfx::Screen. Implemented here to avoid circular
 // dependencies.
-class AURA_EXPORT ScreenAura : public gfx::Screen {
+class ASH_EXPORT ScreenAsh : public gfx::Screen {
  public:
-  explicit ScreenAura(RootWindow* root_window);
-  virtual ~ScreenAura();
+  explicit ScreenAsh(aura::RootWindow* root_window);
+  virtual ~ScreenAsh();
 
   void set_work_area_insets(const gfx::Insets& insets) {
     work_area_insets_ = insets;
@@ -50,11 +52,11 @@ class AURA_EXPORT ScreenAura : public gfx::Screen {
   // Insets for the work area.
   gfx::Insets work_area_insets_;
 
-  RootWindow* root_window_;
+  aura::RootWindow* root_window_;
 
-  DISALLOW_COPY_AND_ASSIGN(ScreenAura);
+  DISALLOW_COPY_AND_ASSIGN(ScreenAsh);
 };
 
-}  // namespace aura
+}  // namespace ash
 
-#endif  // UI_AURA_SCREEN_AURA_H_
+#endif  // ASH_SCREEN_ASH_H_
diff --git a/ash/shell.cc b/ash/shell.cc
index ae5ffab6..ad8f835 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -12,6 +12,7 @@
 #include "ash/focus_cycler.h"
 #include "ash/ime/input_method_event_filter.h"
 #include "ash/launcher/launcher.h"
+#include "ash/screen_ash.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_factory.h"
 #include "ash/shell_window_ids.h"
@@ -306,6 +307,7 @@ internal::WorkspaceController* Shell::TestApi::workspace_controller() {
 
 Shell::Shell(ShellDelegate* delegate)
     : root_window_(new aura::RootWindow),
+      screen_(new ScreenAsh(root_window_.get())),
       root_filter_(NULL),
       delegate_(delegate),
       audio_controller_(NULL),
@@ -316,6 +318,7 @@ Shell::Shell(ShellDelegate* delegate)
       desktop_background_mode_(BACKGROUND_IMAGE),
       root_window_layout_(NULL),
       status_widget_(NULL) {
+  gfx::Screen::SetInstance(screen_);
 }
 
 Shell::~Shell() {
@@ -597,6 +600,22 @@ void Shell::RotateFocus(Direction direction) {
                              internal::FocusCycler::BACKWARD);
 }
 
+void Shell::SetScreenWorkAreaInsets(const gfx::Insets& insets) {
+  if (screen_->work_area_insets() == insets)
+    return;
+  screen_->set_work_area_insets(insets);
+  FOR_EACH_OBSERVER(ShellObserver, observers_,
+                    OnScreenWorkAreaInsetsChanged());
+}
+
+void Shell::AddShellObserver(ShellObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void Shell::RemoveShellObserver(ShellObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Shell, private:
 
diff --git a/ash/shell.h b/ash/shell.h
index 92910ce..e6af0db 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -14,7 +14,9 @@
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
 #include "ui/gfx/size.h"
+#include "ui/gfx/insets.h"
 
 class CommandLine;
 
@@ -45,7 +47,9 @@ class NestedDispatcherController;
 class NetworkController;
 class PowerButtonController;
 class PowerStatusController;
+class ScreenAsh;
 class ShellDelegate;
+class ShellObserver;
 class SystemTrayDelegate;
 class SystemTray;
 class VideoDetector;
@@ -152,6 +156,13 @@ class ASH_EXPORT Shell {
   // Rotate focus through containers that can receive focus.
   void RotateFocus(Direction direction);
 
+  // Sets the screen's work area insets, this notifies observers too.
+  void SetScreenWorkAreaInsets(const gfx::Insets& insets);
+
+  // Add/remove observer.
+  void AddShellObserver(ShellObserver* observer);
+  void RemoveShellObserver(ShellObserver* observer);
+
 #if !defined(OS_MACOSX)
   AcceleratorController* accelerator_controller() {
     return accelerator_controller_.get();
@@ -197,6 +208,8 @@ class ASH_EXPORT Shell {
 
   Launcher* launcher() { return launcher_.get(); }
 
+  const ScreenAsh* screen() { return screen_; }
+
   internal::ShelfLayoutManager* shelf() const { return shelf_; }
 
   SystemTray* tray() const { return tray_.get(); }
@@ -234,6 +247,7 @@ class ASH_EXPORT Shell {
   static bool initially_hide_cursor_;
 
   scoped_ptr<aura::RootWindow> root_window_;
+  ScreenAsh* screen_;
 
   internal::RootWindowEventFilter* root_filter_;  // not owned
 
@@ -288,6 +302,8 @@ class ASH_EXPORT Shell {
   // the status area.
   internal::ShelfLayoutManager* shelf_;
 
+  ObserverList<ShellObserver> observers_;
+
   // Can change at runtime.
   BackgroundMode desktop_background_mode_;
 
diff --git a/ash/shell_observer.h b/ash/shell_observer.h
new file mode 100644
index 0000000..0ecf927
--- /dev/null
+++ b/ash/shell_observer.h
@@ -0,0 +1,24 @@
+// 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.
+
+#ifndef ASH_SHELLOBSERVER_H_
+#define ASH_SHELLOBSERVER_H_
+#pragma once
+
+#include "ash/ash_export.h"
+
+namespace ash {
+
+class ASH_EXPORT ShellObserver {
+ public:
+  // Invoked after the screen's work area insets changes.
+  virtual void OnScreenWorkAreaInsetsChanged() {}
+
+ protected:
+  virtual ~ShellObserver() {}
+};
+
+}  // namespace ash
+
+#endif  // ASH_SHELLOBSERVER_H_
diff --git a/ash/wm/base_layout_manager.cc b/ash/wm/base_layout_manager.cc
index 7fc116d..6a5e5e4 100644
--- a/ash/wm/base_layout_manager.cc
+++ b/ash/wm/base_layout_manager.cc
@@ -20,6 +20,7 @@ namespace internal {
 // BaseLayoutManager, public:
 
 BaseLayoutManager::BaseLayoutManager() {
+  Shell::GetInstance()->AddShellObserver(this);
   Shell::GetRootWindow()->AddRootWindowObserver(this);
 }
 
@@ -27,6 +28,7 @@ BaseLayoutManager::~BaseLayoutManager() {
   for (WindowSet::const_iterator i = windows_.begin(); i != windows_.end(); ++i)
     (*i)->RemoveObserver(this);
   Shell::GetRootWindow()->RemoveRootWindowObserver(this);
+  Shell::GetInstance()->RemoveShellObserver(this);
 }
 
 /////////////////////////////////////////////////////////////////////////////
@@ -70,6 +72,9 @@ void BaseLayoutManager::OnRootWindowResized(const gfx::Size& new_size) {
   AdjustWindowSizesForScreenChange();
 }
 
+/////////////////////////////////////////////////////////////////////////////
+// BaseLayoutManager, ash::ShellObserver overrides:
+
 void BaseLayoutManager::OnScreenWorkAreaInsetsChanged() {
   AdjustWindowSizesForScreenChange();
 }
diff --git a/ash/wm/base_layout_manager.h b/ash/wm/base_layout_manager.h
index 79fd1fe..df858c8 100644
--- a/ash/wm/base_layout_manager.h
+++ b/ash/wm/base_layout_manager.h
@@ -9,6 +9,7 @@
 #include <set>
 
 #include "ash/ash_export.h"
+#include "ash/shell_observer.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/aura/layout_manager.h"
@@ -29,6 +30,7 @@ namespace internal {
 // properly.
 class ASH_EXPORT BaseLayoutManager : public aura::LayoutManager,
                                      public aura::RootWindowObserver,
+                                     public ash::ShellObserver,
                                      public aura::WindowObserver {
  public:
   typedef std::set<aura::Window*> WindowSet;
@@ -49,6 +51,8 @@ class ASH_EXPORT BaseLayoutManager : public aura::LayoutManager,
 
   // RootWindowObserver overrides:
   virtual void OnRootWindowResized(const gfx::Size& new_size) OVERRIDE;
+
+  // ash::ShellObserver overrides:
   virtual void OnScreenWorkAreaInsetsChanged() OVERRIDE;
 
   // WindowObserver overrides:
diff --git a/ash/wm/base_layout_manager_unittest.cc b/ash/wm/base_layout_manager_unittest.cc
index b6e4901..f8045a4 100644
--- a/ash/wm/base_layout_manager_unittest.cc
+++ b/ash/wm/base_layout_manager_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "ash/wm/base_layout_manager.h"
 
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/test/ash_test_base.h"
@@ -11,7 +12,6 @@
 #include "base/compiler_specific.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/test/test_windows.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/aura/window.h"
@@ -27,7 +27,7 @@ class BaseLayoutManagerTest : public test::AshTestBase {
 
   virtual void SetUp() OVERRIDE {
     test::AshTestBase::SetUp();
-    Shell::GetRootWindow()->SetScreenWorkAreaInsets(
+    Shell::GetInstance()->SetScreenWorkAreaInsets(
         gfx::Insets(1, 2, 3, 4));
     Shell::GetRootWindow()->SetHostSize(gfx::Size(800, 600));
     aura::Window* default_container = Shell::GetInstance()->GetContainer(
diff --git a/ash/wm/shelf_layout_manager.cc b/ash/wm/shelf_layout_manager.cc
index 6b37e3f..eca4c40c 100644
--- a/ash/wm/shelf_layout_manager.cc
+++ b/ash/wm/shelf_layout_manager.cc
@@ -5,10 +5,10 @@
 #include "ash/wm/shelf_layout_manager.h"
 
 #include "ash/launcher/launcher.h"
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "base/auto_reset.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/gfx/compositor/layer.h"
 #include "ui/gfx/compositor/layer_animation_observer.h"
 #include "ui/gfx/compositor/layer_animator.h"
@@ -43,7 +43,7 @@ ShelfLayoutManager::ShelfLayoutManager(views::Widget* launcher,
 
 ShelfLayoutManager::~ShelfLayoutManager() {
   // Without a shelf we don't need special insets anymore.
-  Shell::GetRootWindow()->SetScreenWorkAreaInsets(gfx::Insets());
+  Shell::GetInstance()->SetScreenWorkAreaInsets(gfx::Insets());
 }
 
 void ShelfLayoutManager::LayoutShelf() {
@@ -58,7 +58,7 @@ void ShelfLayoutManager::LayoutShelf() {
   status_->SetBounds(target_bounds.status_bounds);
   Shell::GetInstance()->launcher()->SetStatusWidth(
       target_bounds.status_bounds.width());
-  Shell::GetRootWindow()->SetScreenWorkAreaInsets(
+  Shell::GetInstance()->SetScreenWorkAreaInsets(
       target_bounds.work_area_insets);
 }
 
@@ -150,7 +150,7 @@ void ShelfLayoutManager::CalculateTargetBounds(bool visible,
 void ShelfLayoutManager::OnImplicitAnimationsCompleted() {
   TargetBounds target_bounds;
   CalculateTargetBounds(visible_, &target_bounds);
-  Shell::GetRootWindow()->SetScreenWorkAreaInsets(
+  Shell::GetInstance()->SetScreenWorkAreaInsets(
       target_bounds.work_area_insets);
 }
 
diff --git a/ash/wm/shelf_layout_manager_unittest.cc b/ash/wm/shelf_layout_manager_unittest.cc
index 8a83cb0..fbf924d 100644
--- a/ash/wm/shelf_layout_manager_unittest.cc
+++ b/ash/wm/shelf_layout_manager_unittest.cc
@@ -5,11 +5,11 @@
 #include "ash/wm/shelf_layout_manager.h"
 
 #include "ash/launcher/launcher.h"
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/test/ash_test_base.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/window.h"
 #include "ui/base/animation/animation_container_element.h"
 #include "ui/gfx/compositor/layer_animator.h"
@@ -51,7 +51,7 @@ TEST_F(ShelfLayoutManagerTest, MAYBE_SetVisible) {
   shelf->LayoutShelf();
   ASSERT_TRUE(shelf->visible());
 
-  const aura::ScreenAura* screen = Shell::GetRootWindow()->screen();
+  const ash::ScreenAsh* screen = Shell::GetInstance()->screen();
   ASSERT_TRUE(screen);
   // Bottom inset should be the max of widget heights.
   EXPECT_EQ(shelf->max_height(), screen->work_area_insets().bottom());
@@ -96,7 +96,7 @@ TEST_F(ShelfLayoutManagerTest, LayoutShelfWhileAnimating) {
   shelf->LayoutShelf();
   ASSERT_TRUE(shelf->visible());
 
-  const aura::ScreenAura* screen = Shell::GetRootWindow()->screen();
+  const ash::ScreenAsh* screen = Shell::GetInstance()->screen();
 
   // Hide the shelf.
   shelf->SetVisible(false);
diff --git a/ash/wm/toplevel_layout_manager_unittest.cc b/ash/wm/toplevel_layout_manager_unittest.cc
index 246c835..dff916a 100644
--- a/ash/wm/toplevel_layout_manager_unittest.cc
+++ b/ash/wm/toplevel_layout_manager_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "ash/wm/toplevel_layout_manager.h"
 
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/test/ash_test_base.h"
@@ -12,7 +13,6 @@
 #include "base/compiler_specific.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/test/test_windows.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/aura/window.h"
@@ -33,7 +33,7 @@ class ToplevelLayoutManagerTest : public test::AshTestBase {
 
   virtual void SetUp() OVERRIDE {
     test::AshTestBase::SetUp();
-    Shell::GetRootWindow()->SetScreenWorkAreaInsets(
+    Shell::GetInstance()->SetScreenWorkAreaInsets(
         gfx::Insets(1, 2, 3, 4));
     Shell::GetRootWindow()->SetHostSize(gfx::Size(800, 600));
     aura::Window* default_container = Shell::GetInstance()->GetContainer(
@@ -105,16 +105,14 @@ TEST_F(ToplevelLayoutManagerTest,
        ResizeMaximizedWindowOnWorkAreaInsetsChange) {
   gfx::Rect bounds(100, 100, 200, 200);
   scoped_ptr<aura::Window> window(CreateTestWindow(bounds));
-  Shell::GetRootWindow()->SetScreenWorkAreaInsets(
-        gfx::Insets(0, 0, 30, 0));
+  Shell::GetInstance()->SetScreenWorkAreaInsets(gfx::Insets(0, 0, 30, 0));
   window->SetProperty(aura::client::kShowStateKey, ui::SHOW_STATE_MAXIMIZED);
   // Maximized window fills the work area.
   EXPECT_EQ(gfx::Screen::GetMonitorWorkAreaNearestWindow(window.get()),
             window->bounds());
 
   // Change work area insets.
-  Shell::GetRootWindow()->SetScreenWorkAreaInsets(
-        gfx::Insets(0, 0, 60, 0));
+  Shell::GetInstance()->SetScreenWorkAreaInsets(gfx::Insets(0, 0, 60, 0));
   // Maximized window fills the changed work area.
   EXPECT_EQ(gfx::Screen::GetMonitorWorkAreaNearestWindow(window.get()),
             window->bounds());
diff --git a/ash/wm/workspace/workspace_event_filter.cc b/ash/wm/workspace/workspace_event_filter.cc
index 84046b9..786c1c5 100644
--- a/ash/wm/workspace/workspace_event_filter.cc
+++ b/ash/wm/workspace/workspace_event_filter.cc
@@ -4,6 +4,7 @@
 
 #include "ash/wm/workspace/workspace_event_filter.h"
 
+#include "ash/screen_ash.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/window_frame.h"
 #include "ash/wm/window_util.h"
@@ -11,7 +12,6 @@
 #include "ash/wm/workspace/workspace_window_resizer.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/event.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/base/hit_test.h"
diff --git a/ash/wm/workspace/workspace_layout_manager.cc b/ash/wm/workspace/workspace_layout_manager.cc
index 52c50c4..b984493 100644
--- a/ash/wm/workspace/workspace_layout_manager.cc
+++ b/ash/wm/workspace/workspace_layout_manager.cc
@@ -4,6 +4,7 @@
 
 #include "ash/wm/workspace/workspace_layout_manager.h"
 
+#include "ash/screen_ash.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace/workspace.h"
@@ -12,7 +13,6 @@
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/ui_base_types.h"
diff --git a/ash/wm/workspace/workspace_manager.cc b/ash/wm/workspace/workspace_manager.cc
index caf7d93..1aaa8d0 100644
--- a/ash/wm/workspace/workspace_manager.cc
+++ b/ash/wm/workspace/workspace_manager.cc
@@ -6,6 +6,7 @@
 
 #include <algorithm>
 
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/shelf_layout_manager.h"
@@ -19,7 +20,6 @@
 #include "base/stl_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/window.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/gfx/compositor/layer.h"
@@ -288,7 +288,7 @@ void WorkspaceManager::SetActiveWorkspace(Workspace* workspace) {
 
 gfx::Rect WorkspaceManager::GetWorkAreaBounds() {
   gfx::Rect bounds(workspace_size_);
-  bounds.Inset(Shell::GetRootWindow()->screen()->work_area_insets());
+  bounds.Inset(Shell::GetInstance()->screen()->work_area_insets());
   return bounds;
 }
 
diff --git a/ash/wm/workspace/workspace_manager_unittest.cc b/ash/wm/workspace/workspace_manager_unittest.cc
index a9312ca..20fa704 100644
--- a/ash/wm/workspace/workspace_manager_unittest.cc
+++ b/ash/wm/workspace/workspace_manager_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "ash/wm/workspace/workspace_manager.h"
 
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/test/ash_test_base.h"
@@ -15,7 +16,6 @@
 #include "ash/wm/workspace/workspace_layout_manager.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/window.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/gfx/screen.h"
@@ -174,7 +174,7 @@ TEST_F(WorkspaceManagerTest, ResizeMaximizedWindowOnWorkAreaInsetsChange) {
   EXPECT_EQ(251, w1->bounds().height());
 
   // Maximize the window.
-  Shell::GetRootWindow()->SetScreenWorkAreaInsets(
+  Shell::GetInstance()->SetScreenWorkAreaInsets(
         gfx::Insets(0, 0, 30, 0));
   w1->SetProperty(aura::client::kShowStateKey, ui::SHOW_STATE_MAXIMIZED);
 
@@ -187,7 +187,7 @@ TEST_F(WorkspaceManagerTest, ResizeMaximizedWindowOnWorkAreaInsetsChange) {
   EXPECT_EQ(GetWorkAreaBounds().height(), w1->bounds().height());
 
   // Change work area insets.
-  Shell::GetRootWindow()->SetScreenWorkAreaInsets(
+  Shell::GetInstance()->SetScreenWorkAreaInsets(
         gfx::Insets(0, 0, 60, 0));
 
   // Should be 1 workspace, TYPE_MAXIMIZED with w1, fills the changed work
diff --git a/ash/wm/workspace/workspace_window_resizer_unittest.cc b/ash/wm/workspace/workspace_window_resizer_unittest.cc
index 83b5770..f26460a 100644
--- a/ash/wm/workspace/workspace_window_resizer_unittest.cc
+++ b/ash/wm/workspace/workspace_window_resizer_unittest.cc
@@ -4,12 +4,12 @@
 
 #include "ash/wm/workspace/workspace_window_resizer.h"
 
+#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/wm/property_util.h"
 #include "base/string_number_conversions.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/test/test_window_delegate.h"
 #include "ui/base/hit_test.h"
 
@@ -52,7 +52,7 @@ class WorkspaceWindowResizerTest : public test::AshTestBase {
     root->SetBounds(gfx::Rect(0, 0, 800, kRootHeight));
     gfx::Rect root_bounds(root->bounds());
     EXPECT_EQ(kRootHeight, root_bounds.height());
-    root->SetScreenWorkAreaInsets(gfx::Insets());
+    Shell::GetInstance()->SetScreenWorkAreaInsets(gfx::Insets());
     window_.reset(new aura::Window(&delegate_));
     window_->Init(ui::Layer::LAYER_NOT_DRAWN);
     window_->SetParent(Shell::GetInstance()->GetRootWindow());
@@ -547,7 +547,7 @@ TEST_F(WorkspaceWindowResizerTest, AttachedResize_BOTTOM_2_REMEMBER) {
 TEST_F(WorkspaceWindowResizerTest, AttachedResize_BOTTOM_3) {
   aura::RootWindow* root = Shell::GetInstance()->GetRootWindow();
   root->SetBounds(gfx::Rect(0, 0, 600, 800));
-  root->SetScreenWorkAreaInsets(gfx::Insets());
+  Shell::GetInstance()->SetScreenWorkAreaInsets(gfx::Insets());
 
   window_->SetBounds(gfx::Rect( 300, 100, 300, 200));
   window2_->SetBounds(gfx::Rect(300, 300, 200, 150));
@@ -589,7 +589,7 @@ TEST_F(WorkspaceWindowResizerTest, AttachedResize_BOTTOM_3) {
 TEST_F(WorkspaceWindowResizerTest, AttachedResize_BOTTOM_RememberHeight) {
   aura::RootWindow* root = Shell::GetInstance()->GetRootWindow();
   root->SetBounds(gfx::Rect(0, 0, 600, 800));
-  root->SetScreenWorkAreaInsets(gfx::Insets());
+  Shell::GetInstance()->SetScreenWorkAreaInsets(gfx::Insets());
 
   window_->SetBounds(gfx::Rect( 300, 100, 300, 200));
   window2_->SetBounds(gfx::Rect(300, 300, 200, 150));
diff --git a/chrome/browser/ui/views/accessibility_event_router_views_unittest.cc b/chrome/browser/ui/views/accessibility_event_router_views_unittest.cc
index 24acc13..a6cca5b 100644
--- a/chrome/browser/ui/views/accessibility_event_router_views_unittest.cc
+++ b/chrome/browser/ui/views/accessibility_event_router_views_unittest.cc
@@ -26,6 +26,7 @@
 
 #if defined(USE_AURA)
 #include "ui/aura/root_window.h"
+#include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_stacking_client.h"
 #endif
 
@@ -125,6 +126,7 @@ class AccessibilityEventRouterViewsTest
     views::ViewsDelegate::views_delegate = new AccessibilityViewsDelegate();
 #if defined(USE_AURA)
     root_window_.reset(new aura::RootWindow);
+    gfx::Screen::SetInstance(new aura::TestScreen(root_window_.get()));
     test_stacking_client_.reset(
         new aura::test::TestStackingClient(root_window_.get()));
 #endif
diff --git a/chrome/test/base/browser_with_test_window_test.cc b/chrome/test/base/browser_with_test_window_test.cc
index 209f884..2538644 100644
--- a/chrome/test/base/browser_with_test_window_test.cc
+++ b/chrome/test/base/browser_with_test_window_test.cc
@@ -22,6 +22,7 @@
 #if defined(USE_AURA)
 #include "ui/aura/root_window.h"
 #include "ui/aura/test/test_activation_client.h"
+#include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_stacking_client.h"
 #endif
 
@@ -50,6 +51,7 @@ void BrowserWithTestWindowTest::SetUp() {
   browser_->SetWindowForTesting(window_.get());
 #if defined(USE_AURA)
   root_window_.reset(new aura::RootWindow);
+  gfx::Screen::SetInstance(new aura::TestScreen(root_window_.get()));
   test_activation_client_.reset(
       new aura::test::TestActivationClient(root_window_.get()));
   test_stacking_client_.reset(
diff --git a/content/test/test_renderer_host.cc b/content/test/test_renderer_host.cc
index b37dd1c..14293b7 100644
--- a/content/test/test_renderer_host.cc
+++ b/content/test/test_renderer_host.cc
@@ -14,6 +14,7 @@
 
 #if defined(USE_AURA)
 #include "ui/aura/root_window.h"
+#include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_stacking_client.h"
 #endif
 
@@ -181,6 +182,7 @@ void RenderViewHostTestHarness::Reload() {
 void RenderViewHostTestHarness::SetUp() {
 #if defined(USE_AURA)
   root_window_.reset(new aura::RootWindow);
+  gfx::Screen::SetInstance(new aura::TestScreen(root_window_.get()));
   test_stacking_client_.reset(
       new aura::test::TestStackingClient(root_window_.get()));
 #endif
diff --git a/ui/aura/aura.gyp b/ui/aura/aura.gyp
index bc89200..fafb0f0 100644
--- a/ui/aura/aura.gyp
+++ b/ui/aura/aura.gyp
@@ -86,8 +86,6 @@
         'root_window_view_mac.mm',
         'root_window.cc',
         'root_window.h',
-        'screen_aura.cc',
-        'screen_aura.h',
         'window.cc',
         'window.h',
         'window_delegate.h',
@@ -125,6 +123,8 @@
         'test/test_activation_client.h',
         'test/test_event_filter.cc',
         'test/test_event_filter.h',
+        'test/test_screen.cc',
+        'test/test_screen.h',
         'test/test_stacking_client.cc',
         'test/test_stacking_client.h',
         'test/test_windows.cc',
diff --git a/ui/aura/root_window.cc b/ui/aura/root_window.cc
index 3e84db1..f4db009 100644
--- a/ui/aura/root_window.cc
+++ b/ui/aura/root_window.cc
@@ -22,7 +22,6 @@
 #include "ui/aura/event_filter.h"
 #include "ui/aura/focus_manager.h"
 #include "ui/aura/gestures/gesture_recognizer.h"
-#include "ui/aura/screen_aura.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/base/hit_test.h"
@@ -91,7 +90,6 @@ RootWindow::RootWindow()
       mouse_button_flags_(0),
       last_cursor_(kCursorNull),
       cursor_shown_(true),
-      ALLOW_THIS_IN_INITIALIZER_LIST(screen_(new ScreenAura(this))),
       capture_window_(NULL),
       mouse_pressed_handler_(NULL),
       mouse_moved_handler_(NULL),
@@ -108,7 +106,6 @@ RootWindow::RootWindow()
       should_hold_mouse_moves_(false),
       release_mouse_moves_after_draw_(false) {
   SetName("RootWindow");
-  gfx::Screen::SetInstance(screen_);
   last_mouse_location_ = host_->QueryMouseLocation();
 
   should_hold_mouse_moves_ = !CommandLine::ForCurrentProcess()->HasSwitch(
@@ -155,14 +152,6 @@ gfx::Size RootWindow::GetHostSize() const {
   return rect.size();
 }
 
-void RootWindow::SetScreenWorkAreaInsets(const gfx::Insets& insets) {
-  if (screen_->work_area_insets() == insets)
-    return;
-  screen_->set_work_area_insets(insets);
-  FOR_EACH_OBSERVER(RootWindowObserver, observers_,
-                    OnScreenWorkAreaInsetsChanged());
-}
-
 void RootWindow::SetCursor(gfx::NativeCursor cursor) {
   last_cursor_ = cursor;
   // A lot of code seems to depend on NULL cursors actually showing an arrow,
diff --git a/ui/aura/root_window.h b/ui/aura/root_window.h
index f734fb4..ba83940 100644
--- a/ui/aura/root_window.h
+++ b/ui/aura/root_window.h
@@ -37,7 +37,6 @@ class RootWindowHost;
 class RootWindowObserver;
 class KeyEvent;
 class MouseEvent;
-class ScreenAura;
 class StackingClient;
 class ScrollEvent;
 class TouchEvent;
@@ -73,7 +72,6 @@ class AURA_EXPORT RootWindow : public ui::CompositorDelegate,
   bool cursor_shown() const { return cursor_shown_; }
   Window* mouse_pressed_handler() { return mouse_pressed_handler_; }
   Window* capture_window() { return capture_window_; }
-  const ScreenAura* screen() { return screen_; }
 
   // Shows the root window host.
   void ShowRootWindow();
@@ -82,9 +80,6 @@ class AURA_EXPORT RootWindow : public ui::CompositorDelegate,
   void SetHostSize(const gfx::Size& size);
   gfx::Size GetHostSize() const;
 
-  // Sets the screen's work area insets, this notifies observers too.
-  void SetScreenWorkAreaInsets(const gfx::Insets& insets);
-
   // Sets the currently-displayed cursor. If the cursor was previously hidden
   // via ShowCursor(false), it will remain hidden until ShowCursor(true) is
   // called, at which point the cursor that was last set via SetCursor() will be
@@ -313,8 +308,6 @@ class AURA_EXPORT RootWindow : public ui::CompositorDelegate,
 
   ObserverList<RootWindowObserver> observers_;
 
-  ScreenAura* screen_;
-
   // The capture window. When not-null, this window receives all the mouse and
   // touch events.
   Window* capture_window_;
diff --git a/ui/aura/root_window_observer.h b/ui/aura/root_window_observer.h
index 930790d..8df353e 100644
--- a/ui/aura/root_window_observer.h
+++ b/ui/aura/root_window_observer.h
@@ -21,9 +21,6 @@ class AURA_EXPORT RootWindowObserver {
   // Invoked after the RootWindow is resized.
   virtual void OnRootWindowResized(const gfx::Size& new_size) {}
 
-  // Invoked after the screen's work area insets changes.
-  virtual void OnScreenWorkAreaInsetsChanged() {}
-
   // Invoked when a window is focused.
   virtual void OnWindowFocused(Window* window) {}
 
diff --git a/ui/aura/test/aura_test_base.cc b/ui/aura/test/aura_test_base.cc
index a7399a8..203e533 100644
--- a/ui/aura/test/aura_test_base.cc
+++ b/ui/aura/test/aura_test_base.cc
@@ -5,6 +5,7 @@
 #include "ui/aura/test/aura_test_base.h"
 
 #include "ui/aura/root_window.h"
+#include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_stacking_client.h"
 
 namespace aura {
@@ -19,6 +20,7 @@ AuraTestBase::~AuraTestBase() {
 void AuraTestBase::SetUp() {
   testing::Test::SetUp();
   root_window_.reset(new aura::RootWindow);
+  gfx::Screen::SetInstance(new aura::TestScreen(root_window_.get()));
   helper_.InitRootWindow(root_window());
   helper_.SetUp();
   stacking_client_.reset(new TestStackingClient(root_window()));
diff --git a/ui/aura/test/test_screen.cc b/ui/aura/test/test_screen.cc
new file mode 100644
index 0000000..e61db9f
--- /dev/null
+++ b/ui/aura/test/test_screen.cc
@@ -0,0 +1,61 @@
+// 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/test/test_screen.h"
+
+#include "base/logging.h"
+#include "ui/aura/root_window.h"
+#include "ui/aura/window.h"
+#include "ui/gfx/native_widget_types.h"
+
+namespace aura {
+
+TestScreen::TestScreen(aura::RootWindow* root_window)
+    : root_window_(root_window) {
+}
+
+TestScreen::~TestScreen() {
+}
+
+gfx::Point TestScreen::GetCursorScreenPointImpl() {
+  return root_window_->last_mouse_location();
+}
+
+gfx::Rect TestScreen::GetMonitorWorkAreaNearestWindowImpl(
+    gfx::NativeWindow window) {
+  return GetBounds();
+}
+
+gfx::Rect TestScreen::GetMonitorAreaNearestWindowImpl(
+    gfx::NativeWindow window) {
+  return GetBounds();
+}
+
+gfx::Rect TestScreen::GetMonitorWorkAreaNearestPointImpl(
+    const gfx::Point& point) {
+  return GetBounds();
+}
+
+gfx::Rect TestScreen::GetMonitorAreaNearestPointImpl(const gfx::Point& point) {
+  return GetBounds();
+}
+
+gfx::NativeWindow TestScreen::GetWindowAtCursorScreenPointImpl() {
+  const gfx::Point point = GetCursorScreenPoint();
+  return root_window_->GetTopWindowContainingPoint(point);
+}
+
+gfx::Rect TestScreen::GetBounds() {
+  return gfx::Rect(root_window_->bounds().size());
+}
+
+gfx::Size TestScreen::GetPrimaryMonitorSizeImpl() {
+  return GetBounds().size();
+}
+
+int TestScreen::GetNumMonitorsImpl() {
+  return 1;
+}
+
+}  // namespace aura
diff --git a/ui/aura/test/test_screen.h b/ui/aura/test/test_screen.h
new file mode 100644
index 0000000..59fe63d
--- /dev/null
+++ b/ui/aura/test/test_screen.h
@@ -0,0 +1,48 @@
+// 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.
+
+#ifndef UI_AURA_TEST_TEST_SCREEN_H_
+#define UI_AURA_TEST_TEST_SCREEN_H_
+#pragma once
+
+#include "base/compiler_specific.h"
+#include "ui/gfx/insets.h"
+#include "ui/gfx/screen.h"
+
+namespace aura {
+class RootWindow;
+
+// A minimal, testing Aura implementation of gfx::Screen.
+class TestScreen : public gfx::Screen {
+ public:
+  explicit TestScreen(aura::RootWindow* root_window);
+  virtual ~TestScreen();
+
+ protected:
+  virtual gfx::Point GetCursorScreenPointImpl() OVERRIDE;
+  virtual gfx::Rect GetMonitorWorkAreaNearestWindowImpl(
+      gfx::NativeView view) OVERRIDE;
+  virtual gfx::Rect GetMonitorAreaNearestWindowImpl(
+      gfx::NativeView view) OVERRIDE;
+  virtual gfx::Rect GetMonitorWorkAreaNearestPointImpl(
+      const gfx::Point& point) OVERRIDE;
+  virtual gfx::Rect GetMonitorAreaNearestPointImpl(
+      const gfx::Point& point) OVERRIDE;
+  virtual gfx::NativeWindow GetWindowAtCursorScreenPointImpl() OVERRIDE;
+  virtual gfx::Size GetPrimaryMonitorSizeImpl() OVERRIDE;
+  virtual int GetNumMonitorsImpl() OVERRIDE;
+
+ private:
+  // We currently support only one monitor. These two methods return the bounds
+  // and work area.
+  gfx::Rect GetBounds();
+
+  aura::RootWindow* root_window_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestScreen);
+};
+
+}  // namespace aura
+
+#endif  // UI_AURA_TEST_TEST_SCREEN_H_
diff --git a/ui/gfx/screen.h b/ui/gfx/screen.h
index cd363b3..a451130 100644
--- a/ui/gfx/screen.h
+++ b/ui/gfx/screen.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -20,7 +20,7 @@ class UI_EXPORT Screen {
  public:
   virtual ~Screen() {}
 
-#if defined(USE_AURA)
+#if defined(USE_ASH)
   // Sets the instance to use. This takes owernship of |screen|, deleting the
   // old instance. This is used on aura to avoid circular dependencies between
   // ui and aura.
diff --git a/ui/gfx/screen_aura.cc b/ui/gfx/screen_ash.cc
index ea4216f..9df6b84 100644
--- a/ui/gfx/screen_aura.cc
+++ b/ui/gfx/screen_ash.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -9,9 +9,8 @@
 
 namespace gfx {
 
-// gfx can't depend upon aura, otherwise we have circular dependencies. So,
-// gfx::Screen is pluggable for aura and Desktop plugs in the real
-// implementation.
+// gfx can't depend upon ash, otherwise we have circular dependencies. So,
+// gfx::Screen is pluggable and Desktop plugs in the real implementation.
 
 // static
 Screen* Screen::instance_ = NULL;
diff --git a/ui/ui.gyp b/ui/ui.gyp
index 1b9480e..5684be6 100644
--- a/ui/ui.gyp
+++ b/ui/ui.gyp
@@ -338,7 +338,7 @@
         'gfx/render_text_win.h',
         'gfx/screen.h',
         'gfx/screen_android.cc',
-        'gfx/screen_aura.cc',
+        'gfx/screen_ash.cc',
         'gfx/screen_gtk.cc',
         'gfx/screen_mac.mm',
         'gfx/screen_wayland.cc',
diff --git a/ui/views/test/views_test_base.cc b/ui/views/test/views_test_base.cc
index f12c26b..7b87f2e 100644
--- a/ui/views/test/views_test_base.cc
+++ b/ui/views/test/views_test_base.cc
@@ -14,6 +14,7 @@
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/test/test_activation_client.h"
+#include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_stacking_client.h"
 #include "ui/base/ime/input_method.h"
 
@@ -88,6 +89,7 @@ void ViewsTestBase::SetUp() {
     views_delegate_.reset(new TestViewsDelegate());
 #if defined(USE_AURA)
   root_window_.reset(new aura::RootWindow);
+  gfx::Screen::SetInstance(new aura::TestScreen(root_window_.get()));
   root_window_->SetProperty(
       aura::client::kRootWindowInputMethodKey,
       test_input_method_.get());
diff --git a/ui/views/widget/native_widget_aura_unittest.cc b/ui/views/widget/native_widget_aura_unittest.cc
index 4196cf3..3f07ef9 100644
--- a/ui/views/widget/native_widget_aura_unittest.cc
+++ b/ui/views/widget/native_widget_aura_unittest.cc
@@ -10,6 +10,7 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/root_window.h"
+#include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_stacking_client.h"
 #include "ui/aura/window.h"
 #include "ui/views/widget/root_view.h"
@@ -34,6 +35,7 @@ class NativeWidgetAuraTest : public testing::Test {
   // testing::Test overrides:
   virtual void SetUp() OVERRIDE {
     root_window_.reset(new aura::RootWindow);
+    gfx::Screen::SetInstance(new aura::TestScreen(root_window_.get()));
     root_window_->SetBounds(gfx::Rect(0, 0, 640, 480));
     root_window_->SetHostSize(gfx::Size(640, 480));
     test_stacking_client_.reset(