Reenable view_manager_unittests

There were a couple of issues:
. Needed to initialize X for multi-threaded use.
. Need to set override_redirect to true, otherwise we don't always get a MapNotify and we end up wedged waiting for it.

I also added a couple of DCHECKs.

BUG=385475
TEST=test only change
[email protected]

Review URL: https://codereview.chromium.org/339633004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@279530 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/mojo/mojo_services.gypi b/mojo/mojo_services.gypi
index fdf93f2..bf751ac3 100644
--- a/mojo/mojo_services.gypi
+++ b/mojo/mojo_services.gypi
@@ -522,6 +522,11 @@
                 '../third_party/mesa/mesa.gyp:osmesa',
               ],
             }],
+            ['use_x11==1', {
+              'dependencies': [
+                '../ui/gfx/x/gfx_x11.gyp:gfx_x11',
+              ],
+            }],
           ],
         },
         {