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

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
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=171048

[mazda, 2012-12-04 01:50:23]

Could you review this change?
This is a part of refactorings necessary to enable modal windows to move across
displays (http://crbut.com/156519).

[sky, 2012-12-04 15:50:37]

Nice cleanup, LGTM

https://codereview.chromium.org/11280283/diff/1/ash/wm/drag_window_controller.cc
File ash/wm/drag_window_controller.cc (right):

https://codereview.chromium.org/11280283/diff/1/ash/wm/drag_window_controller...
ash/wm/drag_window_controller.cc:53: views::corewm::DeepDeleteLayers(layer_);
NULL out layer_ after you do this.

[mazda, 2012-12-04 17:22:48]

https://codereview.chromium.org/11280283/diff/1/ash/wm/drag_window_controller.cc
File ash/wm/drag_window_controller.cc (right):

https://codereview.chromium.org/11280283/diff/1/ash/wm/drag_window_controller...
ash/wm/drag_window_controller.cc:53: views::corewm::DeepDeleteLayers(layer_);
On 2012/12/04 15:50:37, sky wrote:
> NULL out layer_ after you do this.

Done.

[commit-bot: I haz the power, 2012-12-04 18:29:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mazda@chromium.org/11280283/11001

[commit-bot: I haz the power, 2012-12-04 21:18:23]

Change committed as 171048