Introduce CPU(ARM64)

BUG=354405
R=ager@chromium.org

Review URL: https://codereview.chromium.org/209843002

git-svn-id: svn://svn.chromium.org/blink/trunk@169846 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Replace raw pointers to GC allocated objects by members in stack allocated objects.

R=haraken@chromium.org
BUG=

Review URL: https://codereview.chromium.org/208313010

git-svn-id: svn://svn.chromium.org/blink/trunk@169847 bbb929c8-8fbe-4397-9dbb-9b2b20218538