chromeos: Put touch-event support behind a flag (--enable-touch-events) until it's more baked.

BUG=122884
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10165008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133273 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ui/base/ui_base_switches.cc b/ui/base/ui_base_switches.cc
index a5210537..d83c3cd 100644
--- a/ui/base/ui_base_switches.cc
+++ b/ui/base/ui_base_switches.cc
@@ -6,6 +6,9 @@
 
 namespace switches {
 
+// Enable support for touch events.
+const char kEnableTouchEvents[]             = "enable-touch-events";
+
 // The language file that we want to try to open. Of the form
 // language[-country] where language is the 2 letter code from ISO-639.
 const char kLang[]                          = "lang";