Make MessagingBindings use ScriptContextSet::ForEach

Make MessagingBindings use ScriptContextSet::ForEach. This is a long-standing
TODO and should address the dead isolate issue in bug 382179.

BUG=382179
R=rockot@chromium.org
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=276529

[not at google - send to devlin, 2014-06-10 22:57:24]

7 files changed, 177 insertions(+), 186 deletions(-)

[not at google - send to devlin, 2014-06-10 22:58:39]

it's a pretty mechanical change. process is:
- cut contents of for..loops
- create new function in anon namespace FooForScriptContext
- paste
- replace for..loops with ForEach
- cleanup

[Ken Rockot(use gerrit already), 2014-06-11 14:19:00]

LGTM.

As a nit, it would be cool if there were a version of ForEach that didn't take
an id and always matched all extensions. Seeing the "" arguments scattered
around the code is a little weird.

[not at google - send to devlin, 2014-06-11 15:19:44]

Done. I did the same for the NULL RenderView argument.

[not at google - send to devlin, 2014-06-11 15:20:22]

The CQ bit was checked by kalman@chromium.org

[commit-bot: I haz the power, 2014-06-11 15:22:28]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/kalman@chromium.org/327953002/40001

[commit-bot: I haz the power, 2014-06-11 21:00:04]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)

[commit-bot: I haz the power, 2014-06-11 21:14:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-06-11 21:14:52]

Try jobs failed on following builders:
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)

[not at google - send to devlin, 2014-06-12 04:04:00]

The CQ bit was checked by kalman@chromium.org

[commit-bot: I haz the power, 2014-06-12 04:06:02]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/kalman@chromium.org/327953002/40001

[commit-bot: I haz the power, 2014-06-12 04:12:56]

Change committed as 276529