GitLab

Move ImageCursors from ash/wm/ to ui/base/cursors/ and add a
NativeCursorManager implementation for
ShellDesktopController to use.

BUG=364290
TEST=cursor is visible when running app_shell on a Chrome OS
     device and changes after mousing over a link

Review URL: https://codereview.chromium.org/258893002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266694 0039d316-1c4b-4281-b951-d872f2087c98