Don't create cross origins references in the extension system
Don't create cross origins references in the extension system

BUG=504011
TBR=kalman@chromium.org,haraken@chromium.org

Review URL: https://codereview.chromium.org/1235863003

Cr-Commit-Position: refs/heads/master@{#338573}
(cherry picked from commit 3b1351e5ead02ced4a026fcc6c6a24215a428f56)

Review URL: https://codereview.chromium.org/1241683006 .

Cr-Commit-Position: d34a0005849006230ae7ffb1a9693419810a06bc@{#523}
Cr-Branched-From: 40cda19e609fd36fbf5fe489055423e611631abc@{#330231}

Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,PeterWangIntel/chromium-crosswalk