[Extensions] Skip injecting scripts into remote frames with site isolation turned on.
[Extensions] Skip injecting scripts into remote frames with site isolation turned on.

This is admitting defeat by site isolation, for now. It's better than crashing.
It will be properly fixed when permission checks are moved into the browser.

BUG=454917
R=rdevlin.cronin@chromium.org

Review URL: https://codereview.chromium.org/1018163002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#321254}

Fireblend/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,Pluto-tv/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,axinging/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,hgl888/chromium-crosswalk,Fireblend/chromium-crosswalk,Pluto-tv/chromium-crosswalk,ltilve/chromium,Just-D/chromium-1,Just-D/chromium-1,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Pluto-tv/chromium-crosswalk,Just-D/chromium-1,TheTypoMaster/chromium-crosswalk,ltilve/chromium,hgl888/chromium-crosswalk,fujunwei/chromium-crosswalk,Just-D/chromium-1,TheTypoMaster/chromium-crosswalk,fujunwei/chromium-crosswalk,Just-D/chromium-1,chuan9/chromium-crosswalk,fujunwei/chromium-crosswalk,axinging/chromium-crosswalk,ltilve/chromium,TheTypoMaster/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,fujunwei/chromium-crosswalk,fujunwei/chromium-crosswalk,ltilve/chromium,TheTypoMaster/chromium-crosswalk,axinging/chromium-crosswalk,Chilledheart/chromium,chuan9/chromium-crosswalk,Just-D/chromium-1,Chilledheart/chromium,fujunwei/chromium-crosswalk,ltilve/chromium,hgl888/chromium-crosswalk,Fireblend/chromium-crosswalk,Just-D/chromium-1,Chilledheart/chromium,PeterWangIntel/chromium-crosswalk,chuan9/chromium-crosswalk,hgl888/chromium-crosswalk,Just-D/chromium-1,Chilledheart/chromium,axinging/chromium-crosswalk,ltilve/chromium,axinging/chromium-crosswalk,Chilledheart/chromium,Fireblend/chromium-crosswalk,Pluto-tv/chromium-crosswalk,chuan9/chromium-crosswalk,Just-D/chromium-1,Pluto-tv/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,axinging/chromium-crosswalk,chuan9/chromium-crosswalk,Pluto-tv/chromium-crosswalk,axinging/chromium-crosswalk,fujunwei/chromium-crosswalk,hgl888/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,ltilve/chromium,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,Chilledheart/chromium,axinging/chromium-crosswalk,Chilledheart/chromium,axinging/chromium-crosswalk,ltilve/chromium,Pluto-tv/chromium-crosswalk,Pluto-tv/chromium-crosswalk,Fireblend/chromium-crosswalk,axinging/chromium-crosswalk,chuan9/chromium-crosswalk,Chilledheart/chromium,PeterWangIntel/chromium-crosswalk,axinging/chromium-crosswalk,Pluto-tv/chromium-crosswalk,chuan9/chromium-crosswalk,hgl888/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,hgl888/chromium-crosswalk,ltilve/chromium,chuan9/chromium-crosswalk,fujunwei/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,Fireblend/chromium-crosswalk,hgl888/chromium-crosswalk,fujunwei/chromium-crosswalk,Chilledheart/chromium,hgl888/chromium-crosswalk,chuan9/chromium-crosswalk