input_method: Remove an unneccessary include of mock_bus.h

BUG=234078
TEST=none

Review URL: https://codereview.chromium.org/59863006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233522 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chromeos/input_method/input_method_engine_ibus_browserttests.cc

@@ -16,7 +16,6 @@
 #include "chromeos/ime/mock_ime_property_handler.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/test_utils.h"
-#include "dbus/mock_bus.h"
 
 namespace chromeos {
 namespace input_method {