Add a policy to allow NTP promotions & default apps to be disabled.

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 76 matching lines @@
 #   policy configuration files. 'dynamic_refresh' controls if the generated
 #   documentation should state that the policy supports dynamic refresh or not.
 #   Supporting dynamic refresh means that Chrome respects the changes to the
 #   policy immediately, without the need for restart.
 #
 # 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: 95
+#   For your editing convenience: highest ID currently used: 96
 #
 # 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 1546 matching lines @@
       'id': 92,
       'caption': '''Maximal number of concurrent connections to the proxy server''',
       'desc': '''Specifies the maximal number of simultanious connections to the proxy server.
 
       Some proxy servers can not handle high number of concurrent connections per client and this can be solved by setting this policy to a lower value.
 
       The value of this policy should be lower than 100 and higher than 6 and the default value is 32.
 
       Some web apps are known to consume many connections with hanging GETs, so lowering below 32 may lead to browser networking hangs if too many such web apps are open. Lower below the default at your own risk.''',
     },
+    {
+      'name': 'HideWebStorePromo',
+      'type': 'main',
+      'supported_on': ['chrome.*:15-', 'chrome_os:0.15-'],
+      'features': {'dynamic_refresh': 0},
+      'example_value': False,
+      'id': 96,
+      'caption': '''Prevent app promotions from appearing on the new tab page''',
+      'desc': '''When set to True, promotions for Chrome Web Store apps will not appear on the new tab page.''',
+    },
 
   ],
   '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''',
@@ skipping 71 matching lines @@
       'desc': '''The name of the feature that indicates for a given policy that changes to it are respected by Chrome without a browser restart''',
       'text': '''Dynamic Policy Refresh'''
     },
     'doc_deprecated': {
       'desc': '''Text appended in parentheses to the policy name to indicate t hat it has been deprecated''',
       'text': 'deprecated',
     }
   },
   'placeholders': [],
 }