Check for a null callback in RendererSurfaceViewManager

Check for a null callback in RendererSurfaceViewManager

Now RSVM ignores surface created messages if there's no
outstanding request instead of trying to call a null
callback.

BUG=627453
Review-Url: https://codereview.chromium.org/2141163003
Cr-Commit-Position: refs/heads/master@{#405322}
(cherry picked from commit abac0bdc0db93d2dba82b057222626506ec52533)

Committed: https://chromium.googlesource.com/chromium/src/+/53e7cbe01847d1db4fc01f946196aa2998e0eef6

[watk, 2016-07-20 00:51:47]

Description was changed from

==========
Check for a null callback in RendererSurfaceViewManager

Now RSVM ignores surface created messages if there's no
outstanding request instead of trying to call a null
callback.

BUG=627453

Review-Url: https://codereview.chromium.org/2141163003
Cr-Commit-Position: refs/heads/master@{#405322}
(cherry picked from commit abac0bdc0db93d2dba82b057222626506ec52533)
==========

to

==========
Check for a null callback in RendererSurfaceViewManager

Now RSVM ignores surface created messages if there's no
outstanding request instead of trying to call a null
callback.

BUG=627453

Review-Url: https://codereview.chromium.org/2141163003
Cr-Commit-Position: refs/heads/master@{#405322}
(cherry picked from commit abac0bdc0db93d2dba82b057222626506ec52533)

Committed:
https://chromium.googlesource.com/chromium/src/+/53e7cbe01847d1db4fc01f946196...
==========

[watk, 2016-07-20 00:51:48]

Committed patchset #1 (id:1) manually as
53e7cbe01847d1db4fc01f946196aa2998e0eef6.