For page cyclers, move power metrics start to WillNavigate.

For page cyclers, move power metrics start to WillNavigate.

Page cycler are considering page loads and not interaction with the
page, so the power metric must take the page load into account.

R=tonyg@chromium.org
BUG=361491
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270075

[dtu, 2014-05-12 18:35:49]

lgtm

[qsr, 2014-05-13 07:48:10]

The CQ bit was checked by qsr@chromium.org

[commit-bot: I haz the power, 2014-05-13 07:48:37]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/qsr@chromium.org/281553002/1

[tonyg, 2014-05-13 08:28:19]

lgtm

[commit-bot: I haz the power, 2014-05-13 09:47:57]

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_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)
  linux_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_rel/bu...)

[commit-bot: I haz the power, 2014-05-13 11:08:27]

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

[commit-bot: I haz the power, 2014-05-13 11:08:27]

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

[qsr, 2014-05-13 11:08:53]

The CQ bit was checked by qsr@chromium.org

[commit-bot: I haz the power, 2014-05-13 11:09:15]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/qsr@chromium.org/281553002/1

[commit-bot: I haz the power, 2014-05-13 11:26:24]

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_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[commit-bot: I haz the power, 2014-05-13 12:15:17]

Change committed as 270075