CrOS: Add a flag to allow easy selection of tablet mode.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index fcbb09014d1237ecede0d85b79c1cb1bd1a6169a..509015d39c25201ff0616c2fd42f9a7a0404d190 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -493,6 +493,15 @@ const char kForceFirstRun[]                 = "force-first-run";
 // Forces Chrome to use localNTP instead of server (GWS) NTP.
 const char kForceLocalNtp[]                 = "force-local-ntp";
 
+// Enables required things for the selected UI mode, regardless of whether the
+// chromebook is currently in the selected UI mode.
+const char kForceTabletMode[]               = "force-tablet-mode";
+
+// Values for the kForceTabletMode flag.
+const char kForceTabletModeAuto[]           = "auto";
+const char kForceTabletModeClamshell[]      = "clamshell";
+const char kForceTabletModeTouchView[]      = "touch_view";
+
 // Forces additional Chrome Variation Ids that will be sent in X-Client-Data
 // header, specified as a 64-bit encoded list of numeric experiment ids. Ids
 // prefixed with the character "t" will be treated as Trigger Variation Ids.