Add policy for ash launcher auto-hide behavior

chrome/app/policy/policy_templates.json

 {
 # policy_templates.json - Metafile for policy templates
 #
 # The content of this file is evaluated as a Python expression.
 #
 # This file is used as input to generate the following policy templates:
 # ADM, ADMX+ADML, MCX/plist and html documentation.
 #
 # Policy templates are user interface definitions or documents about the
 # policies that can be used to configure Chrome. Each policy is a name-value
@@ skipping 94 matching lines @@
 #   templates and documentation. The policy definition list that Chrome sees
 #   will include policies marked with 'future'. If a WIP policy isn't meant to
 #   be seen by the policy providers either, the 'supported_on' key should be set
 #   to an empty list.
 #
 # IDs:
 #   Since a Protocol Buffer definition is generated from this file, unique and
 #   persistent IDs for all fields (but not for groups!) are needed. These are
 #   specified by the 'id' keys of each policy. NEVER CHANGE EXISTING IDs,
 #   because doing so would break the deployed wire format!
-#   For your editing convenience: highest ID currently used: 163
+#   For your editing convenience: highest ID currently used: 164
 #
 # Placeholders:
 #   The following placeholder strings are automatically substituted:
 #     $1 -> Google Chrome / Chromium
 #     $2 -> Google Chrome OS / Chromium OS
 #     $3 -> Google Chrome Frame / Chromium Frame
 #     $6 is reserved for doc_writer
 #
 # Device Policy:
 #   An additional flag device_only (optional, defaults to False) indicates
@@ skipping 3151 matching lines @@
       'id': 158,
       'caption': '''Timezone''',
       'desc': '''Specifies the timezone to be used for the device. Users can override the specified timezone for the current session. However, on logout it is set back to the specified timezone. If an invalid value is provided, the policy is still activated using "GMT" instead.
 
       If this policy is not used, the currently active timezone will remain in use however users can change the timezone and the change is persistent. Thus a change by one user affects the login-screen and all other users.
 
       New devices start out with the timezone set to "US/Pacific".
 
       The format of the value follows the names of timezones in the "IANA Time Zone Database" (see "http://en.wikipedia.org/wiki/List_of_tz_database_time"). In particular, most timezones can be referred to by "continent/large_city" or "ocean/large_city".''',
     },
+    {
+      'name': 'ShelfAutoHideBehavior',
+      'type': 'string-enum',
+      'schema': {
+        'type': 'string',
+        'enum': [
+          'Always',
+          'Never'
+        ],
+      },
+      'items': [
+        {
+          'name': 'AlwaysAutoHideShelf',
+          'value': 'Always',
+          'caption': '''Always auto-hide the shelf''',
+        },
+        {
+          'name': 'NeverAutoHideShelf',
+          'value': 'Never',
+          'caption': '''Never auto-hide the shelf''',
+        },
+      ],
+      'supported_on': ['chrome_os:25-'],
+      'features': {
+        'dynamic_refresh': True,
+        'can_be_recommended': True,
+      },
+      'example_value': 'Always',
+      'id': 164,
+      'caption': '''Control shelf auto-hiding''',
+      'desc': '''Control auto-hiding of the <ph name="PRODUCT_OS_NAME">$2<ex>Google Chrome OS</ex></ph> shelf.
+
+      If this policy is set to 'AlwaysAutoHideShelf', the shelf will always auto-hide.
+
+      If this policy is set to 'NeverAutoHideShelf', the shelf never auto-hide.
+
+      If you set this policy, users cannot change or override it.
+
+      If the policy is left not set, users can choose whether the shelf should auto-hide.''',
+    },
   ],
   'messages': {
     # Messages that are not associated to any policies.
     'win_supported_winxpsp2': {
       'desc': '''A label specifying the oldest possible compatible version of Windows. This text will appear right next to a label containing the text 'Supported on:'.''',
       'text': '''Microsoft Windows XP SP2 or later'''
     },
     'mac_chrome_preferences': {
       'desc': '''A text indicating in Mac OS X Workgroup Manager, that currently the preferences of Chrome are being edited''',
       'text': '''<ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> preferences'''
@@ skipping 78 matching lines @@
       'desc': '''Text appended in parentheses to the policy name to indicate that it has been deprecated''',
       'text': 'deprecated',
     },
     'doc_recommended': {
       'desc': '''Text appended in parentheses next to the policies top-level container to indicate that those policies are of the Recommended level''',
       'text': 'Default Settings (users can override)',
     },
   },
   'placeholders': [],
 }