The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/035dc06b3166034bcf3a06a97304f8d80b04f06c

commit 035dc06b3166034bcf3a06a97304f8d80b04f06c
Author: jamescook <jamescook@chromium.org>
Date: Fri Aug 05 21:13:52 2016

mash: Migrate ash::DragImageView to wm common types

It is a dependency of ShelfView, which we're trying to convert.

* Change context parameter to be a WmWindow root_window.
* Initialize Widget using wm common utils.
* Use display::Display to get the device scale factor to size the image.
* Explicitly cancel a drag when a monitor is disconnected. This used to be
handled by marking the aura::Window as not owned by its parent. However,
drags are canceled anyway when monitor disconnects occur -- this just makes
it explicit.
* Added unit test for monitor disconnect during drag.

The DragDropController is not changed because it will likely need to be
refactored or replaced for mus. The new test is written with aura windows
for the same reason.

BUG= 633324 
TEST=ash_unittests

Review-Url: https://codereview.chromium.org/2206033002
Cr-Commit-Position: refs/heads/master@{#410161}

[modify] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/ash.gyp
[add] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/common/drag_drop/OWNERS
[rename] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/common/drag_drop/drag_image_view.cc
[rename] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/common/drag_drop/drag_image_view.h
[modify] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/drag_drop/drag_drop_controller.cc
[modify] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/drag_drop/drag_drop_controller.h
[modify] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/drag_drop/drag_drop_controller_unittest.cc
[modify] https://crrev.com/035dc06b3166034bcf3a06a97304f8d80b04f06c/ash/shelf/shelf_view.cc