Revert 222689 "Use an X event loop in the GPU process on Linux."

Revert 222689 "Use an X event loop in the GPU process on Linux."

> Use an X event loop in the GPU process on Linux.
> 
> In future patches, X windows will be created in the GPU
> process, and events sent to these windows will need to
> be forwarded to their parent windows.
> 
> Linux uses GTK as the default UI event loop type, but
> GTK is not in the GPU process, so the X11 event loop
> type is used instead.
> 
> Update package dependencies.
> 
> BUG=145600
> TBR=thakis, piman
> 
> Review URL: https://chromiumcodereview.appspot.com/23710029

Broke nacl-sizes:
PERF_REGRESS: nacl_helper-text/text (0.11%), nacl_helper-text/text (0.11%)
http://build.chromium.org/p/chromium/buildstatus?builder=Linux%20x64&number=55508

Please add a suppression or remove the inclusion from nacl_helper.

TBR=ccameron@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=222694

[DaleCurtis, 2013-09-12 01:49:31]

Committed patchset #1 manually as r222694.