PlzNavigate: Initialize the renderer on commit

PlzNavigate: Initialize the renderer on commit

This CL makes sure that the renderer is initialized before being used to handle
a navigation that has just committed.

BUG=376082
Committed: https://crrev.com/2d298babb173025d622fd82da6486d0fa77154cb
Cr-Commit-Position: refs/heads/master@{#293191}

[clamy, 2014-09-02 19:44:54]

clamy@chromium.org changed reviewers:
+ carlosk@chromium.org, nasko@chromium.org

[clamy, 2014-09-02 19:46:18]

@nasko: PTAL
@carlosk: FYI

I realized that I forgot to initialize the RenderViewHost after we have picked a
renderer in CommitNavigation. This CL fixes that.

[nasko, 2014-09-03 16:07:10]

LGTM

[clamy, 2014-09-03 17:15:30]

The CQ bit was checked by clamy@chromium.org

[commit-bot: I haz the power, 2014-09-03 17:17:13]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/clamy@chromium.org/536473002/1

[commit-bot: I haz the power, 2014-09-03 18:27:55]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_chromium_rel_swarming on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)
  win_chromium_x64_rel_swarming on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[commit-bot: I haz the power, 2014-09-03 19:42:47]

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

[commit-bot: I haz the power, 2014-09-03 19:42:47]

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

[clamy, 2014-09-03 19:48:46]

The CQ bit was checked by clamy@chromium.org

[commit-bot: I haz the power, 2014-09-03 19:50:23]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/clamy@chromium.org/536473002/1

[commit-bot: I haz the power, 2014-09-03 20:29:56]

Committed patchset #1 (id:1) as bf58d5e0f36ab33c7f0edb01930b113698de1df0

[commit-bot: I haz the power, 2014-09-10 03:27:35]

Patchset 1 (id:??) landed as
https://crrev.com/2d298babb173025d622fd82da6486d0fa77154cb
Cr-Commit-Position: refs/heads/master@{#293191}