Revert of Use the default dispatcher where possible for nested message loops.

Revert of Use the default dispatcher where possible for nested message loops. (https://codereview.chromium.org/182143002/)

Reason for revert:
win debug interactive_ui_tests:

BookmarkBarViewTest12.CloseWithModalDialog (run #1):
[ RUN      ] BookmarkBarViewTest12.CloseWithModalDialog
[3940:2156:0226/224958:2493504:FATAL:desktop_dispatcher_client.cc(33)] Check failed: !quit_closure_.is_null(). 

Original issue's description:
> Use the default dispatcher where possible for nested message loops.
> 
> Notable changes:
>  * Add QuitNestedMessageLoop() to client::DispatcherClient, which can be used to
>    terminate a nested loop started by RunWithDispatcher().
>  * FirstRunDialog and SimpleMessageBoxViews are no longer
>    MessagePumpDispatchers. The default dispatcher is used instead, and
>    QuitNestedMessageLoop() is called to terminate the loop instead of returning
>    POST_DISPATCH_QUIT_LOOP from the Dispatch() override.
> 
> BUG=none
> R=sky@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=253723

TBR=sky@chromium.org,sadrul@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=253744

[scottmg, 2014-02-27 07:45:48]

Created Revert of Use the default dispatcher where possible for nested message
loops.

[commit-bot: I haz the power, 2014-02-27 07:46:23]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/scottmg@chromium.org/182753002/1

[commit-bot: I haz the power, 2014-02-27 07:47:13]

Change committed as 253744