Add confirmation dialog when enabling a 3rd party IME.

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="chromeos">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <message name="IDS_CHROMEBOOK" desc="The localized name for Chromebook.">
     Chromebook
   </message>
   <message name="IDS_CHROMEBOX" desc="The localized name for Chromebox">
@@ skipping 3216 matching lines @@
     Configure...
   </message>
   <message name="IDS_OPTIONS_SETTINGS_LANGUAGES_INPUT_METHOD"
            desc="The label for the section header for input methods">
     Input Method
   </message>
   <message name="IDS_OPTIONS_SETTINGS_LANGUAGES_NO_INPUT_METHODS"
            desc="The label for languages with no Input Methods">
     This language doesn't have any input methods
   </message>
+  <message name="IDS_OPTIONS_SETTINGS_LANGUAGES_THIRD_PARTY_WARNING_TITLE"
+           desc="The title showing in the warning dialog when enabling a 3rd party Input Method">
+    Third party input method
+  </message>
+  <message name="IDS_OPTIONS_SETTINGS_LANGUAGES_THIRD_PARTY_WARNING_MESSAGE"
+           desc="The description showing in the warning dialog when enabling a 3rd party Input Method">
+    This input method may be able to collect all the text you type, including personal data like passwords and credit card numbers. It comes from the extension &quot;<ph name="EXTENSION_NAME">$1<ex>Google Input Tools extension</ex></ph>&quot;. Use this input method?
+  </message>
   <message name="IDS_OPTIONS_SETTINGS_LANGUAGES_SIGN_OUT_BUTTON"
            desc="The label for the sign out button for changing UI language">
     Sign out
   </message>
   <message name="IDS_OPTIONS_SETTINGS_LANGUAGES_PLEASE_ADD_ANOTHER_INPUT_METHOD"
            desc="Warning invoked when the user tries to remove the last input method">
     Please add another input method before removing this one.
   </message>
   <message name="IDS_OPTIONS_SETTINGS_LANGUAGES_INPUT_METHOD_INSTRUCTIONS"
            desc="Explanatory message about how to select input methods">
@@ skipping 2207 matching lines @@
   <message name="IDS_SET_TIME_BUTTON_CLOSE" desc="Text for the button to close the window.">
     Done
   </message>
   <message name="IDS_SET_TIME_DATE_LABEL" desc="Label for the date input element.">
     System date
   </message>
   <message name="IDS_SET_TIME_TIME_LABEL" desc="Label for the time input element.">
     System time
   </message>
 </grit-part>