Add support for arm64 architecture

BUG=314720
R=mad@chromium.org
TBR=cpu@chromium.org

Review URL: https://codereview.chromium.org/153273006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250451 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250451
Blink roll 166855:166934

http://build.chromium.org/f/chromium/perf/dashboard/ui/changelog_blink.html?url=/trunk&range=166856:166934&mode=html
TBR=
BUG=

Review URL: https://codereview.chromium.org/159813003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250452 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250453 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250453