Don't leave renderer process frozen when canceling JavaScript dialogs.

BUG=297289
TEST=See bug for repro steps.
R=avi@chromium.org, sky@chromium.org

Review URL: https://codereview.chromium.org/24436003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225253 0039d316-1c4b-4281-b951-d872f2087c98
Reland linux_aura: Implement most of DesktopScreenX11.

[[Making changes to '_toolset=="target"' section in system.gyp to fix
cros compiling.]]

The linux_aura port didn't deal with multiple monitors very well because
it was treating the X root window as one big display. When xrandr is
present, get the screen areas from it, and exposes this data back to
chrome.

This patch also factors out the EDID parser than chromeos was using into
a common directory. Like chromeos, we use it to assign stable display
IDs.

BUG=287972
TBR=brettw@chromium.org, derat@chromium.org, sky@chromium.org
First Review URL: https://codereview.chromium.org/23536057

Review URL: https://codereview.chromium.org/24459002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225254 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225254