Screen cleanup:
* Split ScreenAsh to ScreenUtil (set of utility functions) and the screen implementation.
* moved screen_ash from Shell to DisplayManager. Ash specific imp is now hidden in DisplayManager.
* Shell now creates a separate screen object which simply keeps the list of displays for shutdown. This allow all screen operation valid during shutdown.

BUG=None
TBR=hongbo.min@intel.com,sky@chromium.org

Review URL: https://codereview.chromium.org/138003007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245562 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245562
Convert the re2 GYP targets to be generated by GN.

BUG=288991
R=bradnelson@google.com
Reland of r245254

Review URL: https://codereview.chromium.org/141053003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245563 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245563