Add ImeMenuTray element.

ash/ash_chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from ash_strings.grd).
      Everything in this file is wrapped in <if expr="chromeos">. -->
 <grit-part>
 
   <!-- Device types -->
   <message name="IDS_ASH_CHROMEBASE" desc="The device name for a Chromebase (versus say Chromebox)">
     Chromebase
   </message>
   <message name="IDS_ASH_CHROMEBIT" desc="The device name for a Chromebit (versus say Chromebox)">
@@ skipping 480 matching lines @@
   <message name="IDS_ASH_HATS_NOTIFICATION_TITLE" desc="The title of the notification for Happiness Tracking Survey.">
     Help us improve Chromebooks
   </message>
   <message name="IDS_ASH_HATS_NOTIFICATION_BODY" desc="The body of the notification for Happiness Tracking Survey.">
     <!-- TODO(malaykeshav): Implement the actual HaTS notification strings -->
     Chrome OS HaTS survey text here. Chrome OS HaTS survey text here. Chrome OS HaTS survey text here. Chrome OS HaTS survey text here.
   </message>
   <message name="IDS_ASH_HATS_NOTIFICATION_TAKE_SURVEY_BUTTON" desc="The title of the button in the notification for Happiness Tracking Survey to take the said survey.">
     Take our survey
   </message>
+  <message name="IDS_ASH_IME_MENU_ACCESSIBLE_NAME" desc="The accessible text for opt-in IME menu icon in status tray.">
+    IME menu button
+  </message>
 
   <!-- Quick Unlock Strings -->
    <message name="IDS_ASH_QUICK_UNLOCK_NOTIFICATION_TITLE" desc="The title of the notification for Quick Unlock feature notification.">
     QU Feature notification title here
   </message>
   <message name="IDS_ASH_QUICK_UNLOCK_NOTIFICATION_BODY" desc="The body of the notification for Quick Unlock feature notification.">
     QU Feature notification body goes here. QU Feature notification body goes here. QU Feature notification body goes here. QU Feature notification body goes here. QU Feature notification body goes here.
   </message>
 
   <!-- Deprecated Accelerators Messages -->
@@ skipping 22 matching lines @@
   </message>
   <message name="IDS_DEPRECATED_SHOW_TASK_MANAGER_MSG"
            desc="Notification message to tell users about the deprecation of Shift+ESC shortcut to show the task manager.">
     The shortcut to open the task manager has changed. Please use <ph name="NEW_SHORTCUT">$1<ex>Search+Esc</ex></ph> instead of <ph name="OLD_SHORTCUT">$2<ex>Shift+Esc</ex></ph>.
   </message>
   <message name="IDS_DEPRECATED_NEXT_IME_MSG"
            desc="Notification message to tell users about the deprecation of Shift+Alt shortcut to switch to the next input method.">
     The shortcut to switch to the next input method has changed. Please use <ph name="NEW_SHORTCUT">$1<ex>Ctrl+Shift+Space</ex></ph> instead of <ph name="OLD_SHORTCUT">$2<ex>Shift+Alt</ex></ph>.
   </message>
 </grit-part>