Add about:flags for enabling gamepad.

chrome/app/generated_resources.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 This file contains definitions of resources that will be translated for each
 locale.  The variables is_win, is_macosx, is_linux, and is_posix are available
 for making strings OS specific.  Other platform defines such as use_titlecase
 are declared in build/common.gypi.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
@@ skipping 4866 matching lines @@
       </message>
       <message name="IDS_FLAGS_ENABLE_POINTER_LOCK_DESCRIPTION" desc="Description for the flag to enable the mouse lock feature.">
         Web pages may capture the mouse pointer and remove it from the user's control. The mouse movement data is directed solely to the web application. Users can escape by pressing the 'Esc' key.
       </message>
       <message name="IDS_FLAGS_ENABLE_PLATFORM_APPS_NAME" desc="Title for the flag to enable platform apps.">
         Enable platform apps
       </message>
       <message name="IDS_FLAGS_ENABLE_PLATFORM_APPS_DESCRIPTION" desc="Description for the flag to enable platform apps.">
         Enable advanced application capabilities.
       </message>
+      <message name="IDS_FLAGS_ENABLE_GAMEPAD_NAME" desc="Title for the flag to enable gamepad support.">
+        Enable Gamepad
+      </message>
+      <message name="IDS_FLAGS_ENABLE_GAMEPAD_DESCRIPTION" desc="Description for the flag to enable gamepad support.">
+        This API allows web applications to access data from gamepad devices connected to the system.
+      </message>
 
       <!-- Crashes -->
       <message name="IDS_CRASHES_TITLE" desc="Title for the chrome://crashes page.">
         Crashes
       </message>
       <message name="IDS_CRASHES_CRASH_COUNT_BANNER_FORMAT" desc="Format for crash count banner on chrome://crashes">
         Crashes (<ph name="CRASH_COUNT">$1<ex>3</ex></ph>)
       </message>
       <message name="IDS_CRASHES_CRASH_HEADER_FORMAT" desc="Format for crash entry headings on chrome://crashes">
         Crash ID <ph name="CRASH_ID">$1<ex>8fa95dbb6f2ec862</ex></ph>
@@ skipping 9748 matching lines @@
     </messages>
     <structures fallback_to_english="true">
       <!-- Make sure these stay in sync with the structures in generated_resources.grd. -->
       <structure name="IDD_CHROME_FRAME_FIND_DIALOG" file="cf_resources.rc" type="dialog" >
       </structure>
       <structure name="IDD_CHROME_FRAME_READY_PROMPT" file="cf_resources.rc" type="dialog" >
       </structure>
     </structures>
   </release>
 </grit>