More accelerator code leanup

More accelerator code leanup
* Remove null check
* Simplify NestedAcceleratorDelegate interface.

BUG=None
R=sky@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=274560

[sky, 2014-06-02 23:53:33]

LGTM

[oshima, 2014-06-03 00:15:01]

The CQ bit was checked by oshima@chromium.org

[oshima, 2014-06-03 00:15:01]

The CQ bit was unchecked by oshima@chromium.org

[oshima, 2014-06-03 00:15:05]

The CQ bit was checked by oshima@chromium.org

[commit-bot: I haz the power, 2014-06-03 00:17:00]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/oshima@chromium.org/312483002/20001

[oshima, 2014-06-03 00:55:13]

The CQ bit was unchecked by oshima@chromium.org

[oshima, 2014-06-03 00:59:13]

The CQ bit was checked by oshima@chromium.org

[commit-bot: I haz the power, 2014-06-03 01:01:02]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/oshima@chromium.org/312483002/40001

[commit-bot: I haz the power, 2014-06-03 04:42:17]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_chromium_chromeos_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  win_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_compile_...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)
  win_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu/builds/15159)

[commit-bot: I haz the power, 2014-06-03 05:06:08]

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

[commit-bot: I haz the power, 2014-06-03 05:06:08]

Try jobs failed on following builders:
  win_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu/builds/15182)

[oshima, 2014-06-03 10:16:52]

The CQ bit was checked by oshima@chromium.org

[commit-bot: I haz the power, 2014-06-03 10:20:56]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/oshima@chromium.org/312483002/60001

[commit-bot: I haz the power, 2014-06-03 14:04:51]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/12209)

[commit-bot: I haz the power, 2014-06-03 16:58:05]

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

[commit-bot: I haz the power, 2014-06-03 16:58:05]

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

[oshima, 2014-06-03 17:09:15]

On 2014/06/03 16:58:05, I haz the power (commit-bot) wrote:
> Try jobs failed on following builders:
>   win_chromium_rel on tryserver.chromium
>
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

unit_test failures, check deps and nacl failure seem to be unrelated (same tests
are failing on other CQ bots). landing manually.

[oshima, 2014-06-03 17:17:11]

Committed patchset #3 manually as r274560 (presubmit successful).