Move extension API schema registration to ExtensionsClient.

Move extension API schema registration to ExtensionsClient.

BUG=368334
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=272696

[Ken Rockot(use gerrit already), 2014-05-23 00:24:54]

lgtm

[Yoyo Zhou, 2014-05-23 01:02:38]

The CQ bit was checked by yoz@chromium.org

[commit-bot: I haz the power, 2014-05-23 01:03:16]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yoz@chromium.org/296133011/20001

[commit-bot: I haz the power, 2014-05-23 05:13:07]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/18...)

[commit-bot: I haz the power, 2014-05-23 05:23:10]

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

[commit-bot: I haz the power, 2014-05-23 05:23:10]

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

[Ken Rockot(use gerrit already), 2014-05-23 20:50:01]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2014-05-23 20:50:56]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yoz@chromium.org/296133011/20001

[commit-bot: I haz the power, 2014-05-23 21:13:15]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/18...)

[Yoyo Zhou, 2014-05-23 21:28:20]

The CQ bit was unchecked by yoz@chromium.org

[Yoyo Zhou, 2014-05-23 23:02:27]

I had to add ifdefs for ENABLE_EXTENSIONS. =(

That's a temporary solution though. The existing one is that extension_api.cc
has a stub for no-extensions; I'm thinking of doing something similar for
chrome_extensions_client.cc in a follow-up.

[Yoyo Zhou, 2014-05-23 23:02:32]

The CQ bit was checked by yoz@chromium.org

[commit-bot: I haz the power, 2014-05-23 23:04:18]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yoz@chromium.org/296133011/40001

[commit-bot: I haz the power, 2014-05-24 03:14:49]

Change committed as 272696