Extract the code of showing a dragging window on another display from PhantomWindowController.

PhantomWindowController shows two styles of window, STYLE_SHADOW and STYLE_DRAGGING.
Although STYLE_SHADOW is specific to workspace, STYLE_DRAGGING is not specific to
workspace. This CL separates this feature into two classes so that the
STYLE_DRAGGING part can be used from non-workspace specific code

- Extract the STYLE_DRAGGING part from PhantomWindowController into DragWindowController.
- Move the ownership of the copied window layer from WorkspaceWindowResizer to
  DragWindowController.

BUG=156519


Review URL: https://chromiumcodereview.appspot.com/11280283

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@171048 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 284 insertions, 190 deletions

diff --git a/ash/ash.gyp b/ash/ash.gyp
index 0a8632c..92db1d7 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -299,6 +299,8 @@
         'wm/default_window_resizer.h',
         'wm/dialog_frame_view.cc',
         'wm/dialog_frame_view.h',
+        'wm/drag_window_controller.cc',
+        'wm/drag_window_controller.h',
         'wm/event_client_impl.cc',
         'wm/event_client_impl.h',
         'wm/event_rewriter_event_filter.cc',
diff --git a/ash/shell_window_ids.h b/ash/shell_window_ids.h
index 0a15aeb..465965e 100644
--- a/ash/shell_window_ids.h
+++ b/ash/shell_window_ids.h
@@ -93,7 +93,7 @@ const int kShellWindowId_SettingBubbleContainer = 19;
 // region selector for partial screenshots.
 const int kShellWindowId_OverlayContainer = 20;
 
-// ID of the window created by PhantomWindowController.
+// ID of the window created by PhantomWindowController or DragWindowController.
 const int kShellWindowId_PhantomWindow = 21;
 
 // The topmost container, used for power off animation.
diff --git a/ash/wm/drag_window_controller.cc b/ash/wm/drag_window_controller.cc
new file mode 100644
index 0000000..85e2cb4
--- /dev/null
+++ b/ash/wm/drag_window_controller.cc
@@ -0,0 +1,125 @@
+// 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 "ash/wm/drag_window_controller.h"
+
+#include "ash/shell_window_ids.h"
+#include "ash/wm/window_util.h"
+#include "ui/aura/client/screen_position_client.h"
+#include "ui/aura/window.h"
+#include "ui/compositor/layer.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/views/corewm/shadow_types.h"
+#include "ui/views/corewm/window_util.h"
+#include "ui/views/view.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+namespace internal {
+
+DragWindowController::DragWindowController(aura::Window* window)
+    : window_(window),
+      drag_widget_(NULL),
+      layer_(NULL) {
+}
+
+DragWindowController::~DragWindowController() {
+  Hide();
+}
+
+void DragWindowController::SetDestinationDisplay(
+    const gfx::Display& dst_display) {
+  dst_display_ = dst_display;
+}
+
+void DragWindowController::Show() {
+  if (!drag_widget_)
+    CreateDragWidget(window_->GetBoundsInScreen());
+  drag_widget_->Show();
+}
+
+void DragWindowController::SetBounds(const gfx::Rect& bounds) {
+  DCHECK(drag_widget_);
+  bounds_ = bounds;
+  SetBoundsInternal(bounds);
+}
+
+void DragWindowController::Hide() {
+  if (drag_widget_) {
+    drag_widget_->Close();
+    drag_widget_ = NULL;
+  }
+  if (layer_) {
+    views::corewm::DeepDeleteLayers(layer_);
+    layer_ = NULL;
+  }
+}
+
+void DragWindowController::SetOpacity(float opacity) {
+  DCHECK(drag_widget_);
+  ui::Layer* layer = drag_widget_->GetNativeWindow()->layer();
+  ui::ScopedLayerAnimationSettings scoped_setter(layer->GetAnimator());
+  layer->SetOpacity(opacity);
+}
+
+void DragWindowController::CreateDragWidget(const gfx::Rect& bounds) {
+  DCHECK(!drag_widget_);
+  drag_widget_ = new views::Widget;
+  views::Widget::InitParams params(views::Widget::InitParams::TYPE_POPUP);
+  params.transparent = true;
+  params.parent = window_->parent();
+  params.can_activate = false;
+  params.keep_on_top = true;
+  drag_widget_->set_focus_on_creation(false);
+  drag_widget_->Init(params);
+  drag_widget_->SetVisibilityChangedAnimationsEnabled(false);
+  drag_widget_->GetNativeWindow()->SetName("DragWindow");
+  drag_widget_->GetNativeWindow()->set_id(kShellWindowId_PhantomWindow);
+  // Show shadow for the dragging window.
+  SetShadowType(drag_widget_->GetNativeWindow(),
+                views::corewm::SHADOW_TYPE_RECTANGULAR);
+  SetBoundsInternal(bounds);
+  drag_widget_->StackAbove(window_);
+
+  RecreateWindowLayers();
+  aura::Window* window = drag_widget_->GetNativeWindow();
+  layer_->SetVisible(true);
+  window->layer()->Add(layer_);
+  window->layer()->StackAtTop(layer_);
+
+  // Show the widget after all the setups.
+  drag_widget_->Show();
+
+  // Fade the window in.
+  ui::Layer* widget_layer = drag_widget_->GetNativeWindow()->layer();
+  widget_layer->SetOpacity(0);
+  ui::ScopedLayerAnimationSettings scoped_setter(widget_layer->GetAnimator());
+  widget_layer->SetOpacity(1);
+}
+
+void DragWindowController::SetBoundsInternal(const gfx::Rect& bounds) {
+  aura::Window* window = drag_widget_->GetNativeWindow();
+  aura::client::ScreenPositionClient* screen_position_client =
+      aura::client::GetScreenPositionClient(window->GetRootWindow());
+  if (screen_position_client && dst_display_.is_valid())
+    screen_position_client->SetBounds(window, bounds, dst_display_);
+  else
+    drag_widget_->SetBounds(bounds);
+}
+
+void DragWindowController::RecreateWindowLayers() {
+  DCHECK(!layer_);
+  layer_ = views::corewm::RecreateWindowLayers(window_, true);
+  layer_->set_delegate(window_->layer()->delegate());
+  // Place the layer at (0, 0) of the DragWindowController's window.
+  gfx::Rect layer_bounds = layer_->bounds();
+  layer_bounds.set_origin(gfx::Point(0, 0));
+  layer_->SetBounds(layer_bounds);
+  layer_->SetVisible(false);
+  // Detach it from the current container.
+  layer_->parent()->Remove(layer_);
+}
+
+}  // namespace internal
+}  // namespace ash
diff --git a/ash/wm/drag_window_controller.h b/ash/wm/drag_window_controller.h
new file mode 100644
index 0000000..41eebd9
--- /dev/null
+++ b/ash/wm/drag_window_controller.h
@@ -0,0 +1,97 @@
+// 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_WM_DRAG_WINDOW_CONTROLLER_H_
+#define ASH_WM_DRAG_WINDOW_CONTROLLER_H_
+
+#include "ash/ash_export.h"
+#include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/rect.h"
+
+namespace aura {
+class Window;
+}
+
+namespace ui {
+class Layer;
+}
+
+namespace views {
+class Widget;
+}
+
+namespace ash {
+namespace internal {
+
+// DragWindowController is responsible for showing a semi-transparent window
+// while dragging a window across displays.
+class ASH_EXPORT DragWindowController {
+ public:
+  explicit DragWindowController(aura::Window* window);
+  virtual ~DragWindowController();
+
+  // Sets the display where the window is placed after the window is dropped.
+  void SetDestinationDisplay(const gfx::Display& dst_display);
+
+  // Shows the drag window at the specified location (coordinates of the
+  // parent). If |layer| is non-NULL, it is shown on top of the drag window.
+  // |layer| is owned by the caller.
+  // This does not immediately show the window.
+  void Show();
+
+  // Hides the drag window.
+  void Hide();
+
+  // This is used to set bounds for the drag window immediately. This should
+  // be called only when the drag window is already visible.
+  void SetBounds(const gfx::Rect& bounds);
+
+  // Sets the opacity of the drag window.
+  void SetOpacity(float opacity);
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(WorkspaceWindowResizerTest, DragWindowController);
+
+  // Creates and shows the |drag_widget_| at |bounds|.
+  // |layer| is shown on top of the drag window if it is non-NULL.
+  // |layer| is not owned by this object.
+  void CreateDragWidget(const gfx::Rect& bounds);
+
+  // Sets bounds of the drag window. The window is shown on |dst_display_|
+  // if its id() is valid. Otherwise, a display nearest to |bounds| is chosen.
+  void SetBoundsInternal(const gfx::Rect& bounds);
+
+  // Recreates a fresh layer for |window_| and all its child windows.
+  void RecreateWindowLayers();
+
+  // Window the drag window is placed beneath.
+  aura::Window* window_;
+
+  // The display where the drag is placed. When dst_display_.id() is
+  // kInvalidDisplayID (i.e. the default), a display nearest to the current
+  // |bounds_| is automatically used.
+  gfx::Display dst_display_;
+
+  // Initially the bounds of |window_|. Each time Show() is invoked
+  // |start_bounds_| is then reset to the bounds of |drag_widget_| and
+  // |bounds_| is set to the value passed into Show(). The animation animates
+  // between these two values.
+  gfx::Rect bounds_;
+
+  views::Widget* drag_widget_;
+
+  // The copy of window_->layer() and its children. This object is the owner of
+  // the layer.
+  ui::Layer* layer_;
+
+  DISALLOW_COPY_AND_ASSIGN(DragWindowController);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_WM_DRAG_WINDOW_CONTROLLER_H_
diff --git a/ash/wm/gestures/system_pinch_handler.cc b/ash/wm/gestures/system_pinch_handler.cc
index b95adc8..806f4f9 100644
--- a/ash/wm/gestures/system_pinch_handler.cc
+++ b/ash/wm/gestures/system_pinch_handler.cc
@@ -73,7 +73,7 @@ SystemGestureStatus SystemPinchHandler::ProcessGestureEvent(
       gfx::Rect bounds =
           GetPhantomWindowScreenBounds(target_, event.location());
       if (phantom_state_ != PHANTOM_WINDOW_NORMAL || phantom_.IsShowing())
-        phantom_.Show(bounds, NULL);
+        phantom_.Show(bounds);
       break;
     }
 
diff --git a/ash/wm/workspace/frame_maximize_button.cc b/ash/wm/workspace/frame_maximize_button.cc
index a1c8ca9..f650cdb 100644
--- a/ash/wm/workspace/frame_maximize_button.cc
+++ b/ash/wm/workspace/frame_maximize_button.cc
@@ -389,7 +389,7 @@ void FrameMaximizeButton::UpdateSnap(const gfx::Point& location,
       snap_sizer_->Update(LocationForSnapSizer(location));
       phantom_window_->Show(ScreenAsh::ConvertRectToScreen(
           frame_->GetWidget()->GetNativeView()->parent(),
-          snap_sizer_->target_bounds()), NULL);
+          snap_sizer_->target_bounds()));
     }
     return;
   }
@@ -425,7 +425,7 @@ void FrameMaximizeButton::UpdateSnap(const gfx::Point& location,
     maximizer_->SetSnapType(snap_type_);
   }
   phantom_window_->Show(
-      ScreenBoundsForType(snap_type_, *snap_sizer_.get()), NULL);
+      ScreenBoundsForType(snap_type_, *snap_sizer_.get()));
 }
 
 SnapType FrameMaximizeButton::SnapTypeForLocation(
diff --git a/ash/wm/workspace/phantom_window_controller.cc b/ash/wm/workspace/phantom_window_controller.cc
index d00fd7e..2a60434 100644
--- a/ash/wm/workspace/phantom_window_controller.cc
+++ b/ash/wm/workspace/phantom_window_controller.cc
@@ -8,19 +8,12 @@
 #include "ash/shell_window_ids.h"
 #include "ash/wm/coordinate_conversion.h"
 #include "third_party/skia/include/core/SkCanvas.h"
-#include "ui/aura/client/screen_position_client.h"
-#include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_delegate.h"
-#include "ui/aura/window_observer.h"
 #include "ui/base/animation/slide_animation.h"
-#include "ui/base/animation/tween.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/canvas.h"
-#include "ui/gfx/screen.h"
 #include "ui/gfx/skia_util.h"
-#include "ui/views/corewm/shadow_types.h"
 #include "ui/views/painter.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
@@ -84,20 +77,14 @@ class EdgePainter : public views::Painter {
 PhantomWindowController::PhantomWindowController(aura::Window* window)
     : window_(window),
       phantom_below_window_(NULL),
-      phantom_widget_(NULL),
-      style_(STYLE_SHADOW) {
+      phantom_widget_(NULL) {
 }
 
 PhantomWindowController::~PhantomWindowController() {
   Hide();
 }
 
-void PhantomWindowController::SetDestinationDisplay(
-    const gfx::Display& dst_display) {
-  dst_display_ = dst_display;
-}
-
-void PhantomWindowController::Show(const gfx::Rect& bounds, ui::Layer* layer) {
+void PhantomWindowController::Show(const gfx::Rect& bounds) {
   if (bounds == bounds_)
     return;
   bounds_ = bounds;
@@ -105,7 +92,7 @@ void PhantomWindowController::Show(const gfx::Rect& bounds, ui::Layer* layer) {
     // Show the phantom at the bounds of the window. We'll animate to the target
     // bounds.
     start_bounds_ = window_->GetBoundsInScreen();
-    CreatePhantomWidget(start_bounds_, layer);
+    CreatePhantomWidget(start_bounds_);
   } else {
     start_bounds_ = phantom_widget_->GetWindowBoundsInScreen();
   }
@@ -115,13 +102,6 @@ void PhantomWindowController::Show(const gfx::Rect& bounds, ui::Layer* layer) {
   animation_->Show();
 }
 
-void PhantomWindowController::SetBounds(const gfx::Rect& bounds) {
-  DCHECK(IsShowing());
-  animation_.reset();
-  bounds_ = bounds;
-  SetBoundsInternal(bounds);
-}
-
 void PhantomWindowController::Hide() {
   if (phantom_widget_)
     phantom_widget_->Close();
@@ -132,31 +112,13 @@ bool PhantomWindowController::IsShowing() const {
   return phantom_widget_ != NULL;
 }
 
-void PhantomWindowController::set_style(Style style) {
-  // Cannot change |style_| after the widget is initialized.
-  DCHECK(!phantom_widget_);
-  style_ = style;
-}
-
-void PhantomWindowController::SetOpacity(float opacity) {
-  DCHECK(phantom_widget_);
-  ui::Layer* layer = phantom_widget_->GetNativeWindow()->layer();
-  ui::ScopedLayerAnimationSettings scoped_setter(layer->GetAnimator());
-  layer->SetOpacity(opacity);
-}
-
-float PhantomWindowController::GetOpacity() const {
-  DCHECK(phantom_widget_);
-  return phantom_widget_->GetNativeWindow()->layer()->opacity();
-}
-
 void PhantomWindowController::AnimationProgressed(
     const ui::Animation* animation) {
-  SetBoundsInternal(animation->CurrentValueBetween(start_bounds_, bounds_));
+  phantom_widget_->SetBounds(
+      animation->CurrentValueBetween(start_bounds_, bounds_));
 }
 
-void PhantomWindowController::CreatePhantomWidget(const gfx::Rect& bounds,
-                                                  ui::Layer* layer) {
+void PhantomWindowController::CreatePhantomWidget(const gfx::Rect& bounds) {
   DCHECK(!phantom_widget_);
   phantom_widget_ = new views::Widget;
   views::Widget::InitParams params(views::Widget::InitParams::TYPE_POPUP);
@@ -173,29 +135,16 @@ void PhantomWindowController::CreatePhantomWidget(const gfx::Rect& bounds,
   phantom_widget_->SetVisibilityChangedAnimationsEnabled(false);
   phantom_widget_->GetNativeWindow()->SetName("PhantomWindow");
   phantom_widget_->GetNativeWindow()->set_id(kShellWindowId_PhantomWindow);
-  if (style_ == STYLE_SHADOW) {
-    views::View* content_view = new views::View;
-    content_view->set_background(
-        views::Background::CreateBackgroundPainter(true, new EdgePainter));
-    phantom_widget_->SetContentsView(content_view);
-  } else if (style_ == STYLE_DRAGGING) {
-    // Show shadow for the dragging window.
-    SetShadowType(phantom_widget_->GetNativeWindow(),
-                  views::corewm::SHADOW_TYPE_RECTANGULAR);
-  }
-  SetBoundsInternal(bounds);
+  views::View* content_view = new views::View;
+  content_view->set_background(
+      views::Background::CreateBackgroundPainter(true, new EdgePainter));
+  phantom_widget_->SetContentsView(content_view);
+  phantom_widget_->SetBounds(bounds);
   if (phantom_below_window_)
     phantom_widget_->StackBelow(phantom_below_window_);
   else
     phantom_widget_->StackAbove(window_);
 
-  if (layer) {
-    aura::Window* window = phantom_widget_->GetNativeWindow();
-    layer->SetVisible(true);
-    window->layer()->Add(layer);
-    window->layer()->StackAtTop(layer);
-  }
-
   // Show the widget after all the setups.
   phantom_widget_->Show();
 
@@ -206,17 +155,5 @@ void PhantomWindowController::CreatePhantomWidget(const gfx::Rect& bounds,
   widget_layer->SetOpacity(1);
 }
 
-void PhantomWindowController::SetBoundsInternal(const gfx::Rect& bounds) {
-  aura::Window* window = phantom_widget_->GetNativeWindow();
-  aura::client::ScreenPositionClient* screen_position_client =
-      aura::client::GetScreenPositionClient(window->GetRootWindow());
-  if (screen_position_client &&
-      dst_display_.id() != gfx::Display::kInvalidDisplayID) {
-    screen_position_client->SetBounds(window, bounds, dst_display_);
-  } else {
-    phantom_widget_->SetBounds(bounds);
-  }
-}
-
 }  // namespace internal
 }  // namespace ash
diff --git a/ash/wm/workspace/phantom_window_controller.h b/ash/wm/workspace/phantom_window_controller.h
index 7b90615..d7622fc 100644
--- a/ash/wm/workspace/phantom_window_controller.h
+++ b/ash/wm/workspace/phantom_window_controller.h
@@ -10,16 +10,13 @@
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/base/animation/animation_delegate.h"
-#include "ui/gfx/display.h"
 #include "ui/gfx/rect.h"
 
 namespace aura {
-class RootWindow;
 class Window;
 }
 
 namespace ui {
-class Layer;
 class SlideAnimation;
 }
 
@@ -34,17 +31,9 @@ namespace internal {
 // of a window. It's used used during dragging a window to show a snap location.
 class ASH_EXPORT PhantomWindowController : public ui::AnimationDelegate {
  public:
-  enum Style {
-    STYLE_SHADOW,  // for window snapping.
-    STYLE_DRAGGING,  // for window dragging.
-  };
-
   explicit PhantomWindowController(aura::Window* window);
   virtual ~PhantomWindowController();
 
-  // Sets the display where the phantom is placed.
-  void SetDestinationDisplay(const gfx::Display& dst_display);
-
   // Bounds last passed to Show().
   const gfx::Rect& bounds() const { return bounds_; }
 
@@ -52,11 +41,7 @@ class ASH_EXPORT PhantomWindowController : public ui::AnimationDelegate {
   // parent). If |layer| is non-NULL, it is shown on top of the phantom window.
   // |layer| is owned by the caller.
   // This does not immediately show the window.
-  void Show(const gfx::Rect& bounds, ui::Layer* layer);
-
-  // This is used to set bounds for the phantom window immediately. This should
-  // be called only when the phantom window is already visible.
-  void SetBounds(const gfx::Rect& bounds);
+  void Show(const gfx::Rect& bounds);
 
   // Hides the phantom.
   void Hide();
@@ -70,14 +55,6 @@ class ASH_EXPORT PhantomWindowController : public ui::AnimationDelegate {
     phantom_below_window_ = phantom_below_window;
   }
 
-  // Sets/gets the style of the phantom window.
-  void set_style(Style style);
-  Style style() const { return style_; }
-
-  // Sets/gets the opacity of the phantom window.
-  void SetOpacity(float opacity);
-  float GetOpacity() const;
-
   // ui::AnimationDelegate overrides:
   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
 
@@ -87,20 +64,11 @@ class ASH_EXPORT PhantomWindowController : public ui::AnimationDelegate {
   // Creates and shows the |phantom_widget_| at |bounds|.
   // |layer| is shown on top of the phantom window if it is non-NULL.
   // |layer| is not owned by this object.
-  void CreatePhantomWidget(const gfx::Rect& bounds, ui::Layer* layer);
-
-  // Sets bounds of the phantom window. The window is shown on |dst_display_|
-  // if its id() is valid. Otherwise, a display nearest to |bounds| is chosen.
-  void SetBoundsInternal(const gfx::Rect& bounds);
+  void CreatePhantomWidget(const gfx::Rect& bounds);
 
   // Window the phantom is placed beneath.
   aura::Window* window_;
 
-  // The display where the phantom is placed. When dst_display_.id() is
-  // kInvalidDisplayID (i.e. the default), a display nearest to the current
-  // |bounds_| is automatically used.
-  gfx::Display dst_display_;
-
   // If set, the phantom window should get stacked below this window.
   aura::Window* phantom_below_window_;
 
@@ -116,9 +84,6 @@ class ASH_EXPORT PhantomWindowController : public ui::AnimationDelegate {
   // Used to transition the bounds.
   scoped_ptr<ui::SlideAnimation> animation_;
 
-  // The style of the phantom window.
-  Style style_;
-
   DISALLOW_COPY_AND_ASSIGN(PhantomWindowController);
 };
 
diff --git a/ash/wm/workspace/workspace_window_resizer.cc b/ash/wm/workspace/workspace_window_resizer.cc
index b452a12..1229c23 100644
--- a/ash/wm/workspace/workspace_window_resizer.cc
+++ b/ash/wm/workspace/workspace_window_resizer.cc
@@ -17,6 +17,7 @@
 #include "ash/wm/coordinate_conversion.h"
 #include "ash/wm/cursor_manager.h"
 #include "ash/wm/default_window_resizer.h"
+#include "ash/wm/drag_window_controller.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace/phantom_window_controller.h"
@@ -29,7 +30,6 @@
 #include "ui/compositor/layer.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/transform.h"
-#include "ui/views/corewm/window_util.h"
 
 namespace ash {
 
@@ -312,14 +312,6 @@ WorkspaceWindowResizer::~WorkspaceWindowResizer() {
   shell->mouse_cursor_filter()->HideSharedEdgeIndicator();
   shell->cursor_manager()->UnlockCursor();
 
-  // Delete phantom controllers first so that they will never see the deleted
-  // |layer_|.
-  snap_phantom_window_controller_.reset();
-  drag_phantom_window_controller_.reset();
-
-  if (layer_)
-    views::corewm::DeepDeleteLayers(layer_);
-
   if (destroyed_)
     *destroyed_ = true;
 }
@@ -380,16 +372,16 @@ void WorkspaceWindowResizer::Drag(const gfx::Point& location_in_parent,
   }
   // Show a phantom window for dragging in another root window.
   if (HasSecondaryRootWindow())
-    UpdateDragPhantomWindow(bounds, in_original_root);
+    UpdateDragWindow(bounds, in_original_root);
   else
-    drag_phantom_window_controller_.reset();
+    drag_window_controller_.reset();
 
 }
 
 void WorkspaceWindowResizer::CompleteDrag(int event_flags) {
   wm::SetUserHasChangedWindowPositionOrSize(details_.window, true);
   window()->layer()->SetOpacity(details_.initial_opacity);
-  drag_phantom_window_controller_.reset();
+  drag_window_controller_.reset();
   snap_phantom_window_controller_.reset();
   if (!did_move_or_resize_ || details_.window_component != HTCAPTION)
     return;
@@ -431,7 +423,7 @@ void WorkspaceWindowResizer::CompleteDrag(int event_flags) {
 
 void WorkspaceWindowResizer::RevertDrag() {
   window()->layer()->SetOpacity(details_.initial_opacity);
-  drag_phantom_window_controller_.reset();
+  drag_window_controller_.reset();
   snap_phantom_window_controller_.reset();
   Shell::GetInstance()->mouse_cursor_filter()->HideSharedEdgeIndicator();
 
@@ -477,7 +469,6 @@ WorkspaceWindowResizer::WorkspaceWindowResizer(
       total_initial_size_(0),
       snap_type_(SNAP_NONE),
       num_mouse_moves_since_bounds_change_(0),
-      layer_(NULL),
       destroyed_(NULL),
       magnetism_window_(NULL) {
   DCHECK(details_.is_resizable);
@@ -827,8 +818,8 @@ int WorkspaceWindowResizer::PrimaryAxisCoordinate(int x, int y) const {
   return 0;
 }
 
-void WorkspaceWindowResizer::UpdateDragPhantomWindow(const gfx::Rect& bounds,
-                                                     bool in_original_root) {
+void WorkspaceWindowResizer::UpdateDragWindow(const gfx::Rect& bounds,
+                                              bool in_original_root) {
   if (!did_move_or_resize_ || details_.window_component != HTCAPTION ||
       !ShouldAllowMouseWarp()) {
     return;
@@ -852,26 +843,22 @@ void WorkspaceWindowResizer::UpdateDragPhantomWindow(const gfx::Rect& bounds,
       in_original_root ? 1 : (kMaxOpacity * (1 - fraction_in_another_window));
 
   if (fraction_in_another_window > 0) {
-    if (!drag_phantom_window_controller_.get()) {
-      drag_phantom_window_controller_.reset(
-          new PhantomWindowController(window()));
-      drag_phantom_window_controller_->set_style(
-          PhantomWindowController::STYLE_DRAGGING);
+    if (!drag_window_controller_.get()) {
+      drag_window_controller_.reset(
+          new DragWindowController(window()));
       // Always show the drag phantom on the |another_root| window.
-      drag_phantom_window_controller_->SetDestinationDisplay(
+      drag_window_controller_->SetDestinationDisplay(
           Shell::GetScreen()->GetDisplayMatching(
               another_root->GetBoundsInScreen()));
-      if (!layer_)
-        RecreateWindowLayers();
-      drag_phantom_window_controller_->Show(bounds_in_screen, layer_);
+      drag_window_controller_->Show();
     } else {
       // No animation.
-      drag_phantom_window_controller_->SetBounds(bounds_in_screen);
+      drag_window_controller_->SetBounds(bounds_in_screen);
     }
-    drag_phantom_window_controller_->SetOpacity(phantom_opacity);
+    drag_window_controller_->SetOpacity(phantom_opacity);
     window()->layer()->SetOpacity(window_opacity);
   } else {
-    drag_phantom_window_controller_.reset();
+    drag_window_controller_.reset();
     window()->layer()->SetOpacity(1.0f);
   }
 }
@@ -907,7 +894,7 @@ void WorkspaceWindowResizer::UpdateSnapPhantomWindow(const gfx::Point& location,
         new PhantomWindowController(window()));
   }
   snap_phantom_window_controller_->Show(ScreenAsh::ConvertRectToScreen(
-      window()->parent(), snap_sizer_->target_bounds()), NULL);
+      window()->parent(), snap_sizer_->target_bounds()));
 }
 
 void WorkspaceWindowResizer::RestackWindows() {
@@ -959,18 +946,5 @@ bool WorkspaceWindowResizer::ShouldAllowMouseWarp() const {
       (window()->type() == aura::client::WINDOW_TYPE_NORMAL);
 }
 
-void WorkspaceWindowResizer::RecreateWindowLayers() {
-  DCHECK(!layer_);
-  layer_ = views::corewm::RecreateWindowLayers(window(), true);
-  layer_->set_delegate(window()->layer()->delegate());
-  // Place the layer at (0, 0) of the PhantomWindowController's window.
-  gfx::Rect layer_bounds = layer_->bounds();
-  layer_bounds.set_origin(gfx::Point(0, 0));
-  layer_->SetBounds(layer_bounds);
-  layer_->SetVisible(false);
-  // Detach it from the current container.
-  layer_->parent()->Remove(layer_);
-}
-
 }  // namespace internal
 }  // namespace ash
diff --git a/ash/wm/workspace/workspace_window_resizer.h b/ash/wm/workspace/workspace_window_resizer.h
index a948cc8..f234a9e 100644
--- a/ash/wm/workspace/workspace_window_resizer.h
+++ b/ash/wm/workspace/workspace_window_resizer.h
@@ -25,6 +25,7 @@ class Layer;
 namespace ash {
 namespace internal {
 
+class DragWindowController;
 class PhantomWindowController;
 class SnapSizer;
 class WindowSize;
@@ -76,7 +77,7 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
                          const std::vector<aura::Window*>& attached_windows);
 
  private:
-  FRIEND_TEST_ALL_PREFIXES(WorkspaceWindowResizerTest, PhantomStyle);
+  FRIEND_TEST_ALL_PREFIXES(WorkspaceWindowResizerTest, DragWindowController);
   FRIEND_TEST_ALL_PREFIXES(WorkspaceWindowResizerTest, CancelSnapPhantom);
   FRIEND_TEST_ALL_PREFIXES(WorkspaceWindowResizerTest, PhantomSnapMaxSize);
 
@@ -168,7 +169,7 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
 
   // Updates the bounds of the phantom window for window dragging. Set true on
   // |in_original_root| if the pointer is still in |window()->GetRootWindow()|.
-  void UpdateDragPhantomWindow(const gfx::Rect& bounds, bool in_original_root);
+  void UpdateDragWindow(const gfx::Rect& bounds, bool in_original_root);
 
   // Restacks the windows z-order position so that one of the windows is at the
   // top of the z-order, and the rest directly underneath it.
@@ -181,9 +182,6 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
   // Returns true if we should allow the mouse pointer to warp.
   bool ShouldAllowMouseWarp() const;
 
-  // Recreates a fresh layer for window() and all its child windows.
-  void RecreateWindowLayers();
-
   aura::Window* window() const { return details_.window; }
 
   const Details details_;
@@ -208,7 +206,7 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
   scoped_ptr<PhantomWindowController> snap_phantom_window_controller_;
 
   // Shows a semi-transparent image of the window being dragged.
-  scoped_ptr<PhantomWindowController> drag_phantom_window_controller_;
+  scoped_ptr<DragWindowController> drag_window_controller_;
 
   // Used to determine the target position of a snap.
   scoped_ptr<SnapSizer> snap_sizer_;
@@ -224,10 +222,6 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
   // The mouse location passed to Drag().
   gfx::Point last_mouse_location_;
 
-  // The copy of window()->layer() and its children. This object is the owner of
-  // the layer.
-  ui::Layer* layer_;
-
   // If non-NULL the destructor sets this to true. Used to determine if this has
   // been deleted.
   bool* destroyed_;
diff --git a/ash/wm/workspace/workspace_window_resizer_unittest.cc b/ash/wm/workspace/workspace_window_resizer_unittest.cc
index b7c8eb0..58ca53f 100644
--- a/ash/wm/workspace/workspace_window_resizer_unittest.cc
+++ b/ash/wm/workspace/workspace_window_resizer_unittest.cc
@@ -13,12 +13,13 @@
 #include "ash/test/ash_test_base.h"
 #include "ash/test/cursor_manager_test_api.h"
 #include "ash/wm/cursor_manager.h"
+#include "ash/wm/drag_window_controller.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/shelf_layout_manager.h"
 #include "ash/wm/window_util.h"
-#include "ash/wm/workspace_controller.h"
-#include "ash/wm/workspace/snap_sizer.h"
 #include "ash/wm/workspace/phantom_window_controller.h"
+#include "ash/wm/workspace/snap_sizer.h"
+#include "ash/wm/workspace_controller.h"
 #include "base/string_number_conversions.h"
 #include "base/stringprintf.h"
 #include "ui/aura/client/aura_constants.h"
@@ -607,8 +608,8 @@ TEST_F(WorkspaceWindowResizerTest,
   }
 }
 
-// Verifies the style of the drag phantom window is correct.
-TEST_F(WorkspaceWindowResizerTest, PhantomStyle) {
+// Verifies the drag window controller is instanciated appropriately.
+TEST_F(WorkspaceWindowResizerTest, DragWindowController) {
   UpdateDisplay("800x600,800x600");
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
   ASSERT_EQ(2U, root_windows.size());
@@ -622,41 +623,42 @@ TEST_F(WorkspaceWindowResizerTest, PhantomStyle) {
         window_.get(), gfx::Point(), HTCAPTION, empty_windows()));
     ASSERT_TRUE(resizer.get());
     EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
-    EXPECT_FALSE(resizer->drag_phantom_window_controller_.get());
+    EXPECT_FALSE(resizer->drag_window_controller_.get());
 
     // The pointer is inside the primary root. Both phantoms should be NULL.
     resizer->Drag(CalculateDragPoint(*resizer, 10, 10), 0);
     EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
-    EXPECT_FALSE(resizer->drag_phantom_window_controller_.get());
+    EXPECT_FALSE(resizer->drag_window_controller_.get());
 
     // The window spans both root windows.
     resizer->Drag(CalculateDragPoint(*resizer, 798, 10), 0);
     EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
-    PhantomWindowController* controller =
-        resizer->drag_phantom_window_controller_.get();
+    DragWindowController* controller =
+        resizer->drag_window_controller_.get();
     ASSERT_TRUE(controller);
-    EXPECT_EQ(PhantomWindowController::STYLE_DRAGGING, controller->style());
+    ASSERT_TRUE(controller->drag_widget_);
+    ui::Layer* drag_layer =
+        controller->drag_widget_->GetNativeWindow()->layer();
+    ASSERT_TRUE(drag_layer);
 
     // Check if |resizer->layer_| is properly set to the phantom widget.
-    const std::vector<ui::Layer*>& layers =
-        controller->phantom_widget_->GetNativeWindow()->layer()->children();
+    const std::vector<ui::Layer*>& layers = drag_layer->children();
     EXPECT_FALSE(layers.empty());
-    EXPECT_EQ(resizer->layer_, layers.back());
+    EXPECT_EQ(controller->layer_, layers.back());
 
     // |window_| should be opaque since the pointer is still on the primary
     // root window. The phantom should be semi-transparent.
     EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
-    EXPECT_GT(1.0f, controller->GetOpacity());
+    EXPECT_GT(1.0f, drag_layer->opacity());
 
     // Enter the pointer to the secondary display.
     resizer->Drag(CalculateDragPoint(*resizer, 800, 10), 0);
     EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
-    controller = resizer->drag_phantom_window_controller_.get();
+    controller = resizer->drag_window_controller_.get();
     ASSERT_TRUE(controller);
-    EXPECT_EQ(PhantomWindowController::STYLE_DRAGGING, controller->style());
     // |window_| should be transparent, and the phantom should be opaque.
     EXPECT_GT(1.0f, window_->layer()->opacity());
-    EXPECT_FLOAT_EQ(1.0f, controller->GetOpacity());
+    EXPECT_FLOAT_EQ(1.0f, drag_layer->opacity());
 
     resizer->CompleteDrag(0);
     EXPECT_EQ(root_windows[1], window_->GetRootWindow());
@@ -673,7 +675,7 @@ TEST_F(WorkspaceWindowResizerTest, PhantomStyle) {
         window_.get(), gfx::Point(), HTCAPTION, empty_windows()));
     ASSERT_TRUE(resizer.get());
     EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
-    EXPECT_FALSE(resizer->drag_phantom_window_controller_.get());
+    EXPECT_FALSE(resizer->drag_window_controller_.get());
 
     resizer->Drag(CalculateDragPoint(*resizer, 0, 610), 0);
     resizer->RevertDrag();
@@ -697,7 +699,7 @@ TEST_F(WorkspaceWindowResizerTest, CancelSnapPhantom) {
         window_.get(), gfx::Point(), HTCAPTION, empty_windows()));
     ASSERT_TRUE(resizer.get());
     EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
-    EXPECT_FALSE(resizer->drag_phantom_window_controller_.get());
+    EXPECT_FALSE(resizer->drag_window_controller_.get());
     EXPECT_EQ(WorkspaceWindowResizer::SNAP_NONE, resizer->snap_type_);
 
     // The pointer is on the edge but not shared.  Both controllers should be
@@ -705,10 +707,9 @@ TEST_F(WorkspaceWindowResizerTest, CancelSnapPhantom) {
     resizer->Drag(CalculateDragPoint(*resizer, 799, 0), 0);
     EXPECT_TRUE(resizer->snap_phantom_window_controller_.get());
     EXPECT_EQ(WorkspaceWindowResizer::SNAP_RIGHT_EDGE, resizer->snap_type_);
-    PhantomWindowController* controller =
-        resizer->drag_phantom_window_controller_.get();
+    DragWindowController* controller =
+        resizer->drag_window_controller_.get();
     ASSERT_TRUE(controller);
-    EXPECT_EQ(PhantomWindowController::STYLE_DRAGGING, controller->style());
 
     // Move the cursor across the edge.  Now the snap phantom controller
     // should be canceled.
@@ -716,9 +717,8 @@ TEST_F(WorkspaceWindowResizerTest, CancelSnapPhantom) {
     EXPECT_FALSE(resizer->snap_phantom_window_controller_.get());
     EXPECT_EQ(WorkspaceWindowResizer::SNAP_NONE, resizer->snap_type_);
     controller =
-        resizer->drag_phantom_window_controller_.get();
+        resizer->drag_window_controller_.get();
     ASSERT_TRUE(controller);
-    EXPECT_EQ(PhantomWindowController::STYLE_DRAGGING, controller->style());
   }
 }