Fix remoting_unittests compilation with Aura

Now XServerErrorHandler compiles in GTK-less builds, so
remoting_unittests can be compiled with Aura.

BUG=114211

Review URL: https://chromiumcodereview.appspot.com/10435004

git-svn-id: http://src.chromium.org/svn/trunk/src/build@138693 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

all.gyp

@@ -553,6 +553,7 @@
             '../chrome/chrome.gyp:chrome',
             '../chrome/chrome.gyp:interactive_ui_tests',            
             '../chrome/chrome.gyp:unit_tests',
+            '../remoting/remoting.gyp:remoting_unittests',
             '../ui/aura/aura.gyp:*',
             '../ui/compositor/compositor.gyp:*',
             '../ui/ui.gyp:gfx_unittests',