Add d8 to the chromium_builder_asan target.

BUG=
R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/142693006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249433 0039d316-1c4b-4281-b951-d872f2087c98
[GCM] Pull backoff policy out into GCM and update values

The default backoff time is now 15 seconds. Additionally, the backoff
policy is now injected into the connection factory, to allow sharing it
with the registration and checking logic.

BUG=284553

Review URL: https://codereview.chromium.org/154743003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249434 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249433
SVN changes up to revision 249434