Remove RenderThread::IsRegisteredExtension

Remove RenderThread::IsRegisteredExtension

It appears to have no callers (the last was removed by r127117).

R=jam@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=150730

[jam, 2012-08-08 18:25:15]

lgtm, thanks!

[commit-bot: I haz the power, 2012-08-08 19:58:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mihaip@chromium.org/10836146/1

[commit-bot: I haz the power, 2012-08-08 21:21:58]

Try job failure for 10836146-1 (retry) on mac_rel for step "browser_tests".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_rel&nu...

[commit-bot: I haz the power, 2012-08-08 22:46:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mihaip@chromium.org/10836146/1

[commit-bot: I haz the power, 2012-08-08 23:26:24]

Try job failure for 10836146-1 (retry) on android for steps "compile, build"
(clobber build).
It's a second try, previously, steps "compile, build" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=android&nu...

[commit-bot: I haz the power, 2012-08-09 00:10:23]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mihaip@chromium.org/10836146/1

[commit-bot: I haz the power, 2012-08-09 01:44:56]

Try job failure for 10836146-1 (retry) (retry) on linux_rel for step
"nacl_integration".
It's a second try, previously, step "nacl_integration" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...