Add a New Tab page location group policy

components/policy/resources/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 121 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: 359
+#   For your editing convenience: highest ID currently used: 360
+#   And don't forget to also update the EnterprisePolicies enum of

[pastarmovj, 2017/01/19 14:56:21]

Good idea! :)

[MAD, 2017/01/19 16:13:30]

Acknowledged.

+#   histograms.xml.
 #
 # 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 125 matching lines @@
           If you enable or disable this setting, users cannot change their homepage type in <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph>.
 
           Leaving this policy not set will allow the user to choose whether the new tab page is their home page on their own.
 
           This policy is not available on Windows instances that are not joined
           to an Active Directory domain.''',
         },
       ],
     },
     {
+      'name': 'NewTabPage',
+      'type': 'group',
+      'caption': '''New Tab Page''',
+      'desc': '''Configure the default New Tab page in <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph>.''',
+      'policies': [
+        {
+          'name': 'NewTabPageLocation',
+          'type': 'string',
+          'schema': { 'type': 'string' },
+          'supported_on': ['chrome.*:57-', 'chrome_os:57-'],
+          'features': {
+            'can_be_recommended': True,
+            'dynamic_refresh': True,
+            'per_profile': True,
+          },
+          'example_value': 'https://www.chromium.org',
+          'id': 360,
+          'caption': '''Configure the New Tab page URL''',
+          'tags': [],
+          'desc': '''Configures the default New Tab page URL in <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> and prevents users from changing it.
+
+          The New Tab page is the page opened when new tabs are created (including the one opened in new windowsa). The pages that open on startup are controlled by the RestoreOnStartup policies, which could be to open the New Tab page.

[pastarmovj, 2017/01/19 14:56:21]

s/windowsa/windows/.

Also I would extend a little bit the second sentence into a paragraph on its own
by stating with something like. "This policy does not decide which pages to be
opened on start up. They are controlled by ...."

[MAD, 2017/01/19 16:13:30]

Done.

+
+          The NewTabPageLocation can be set to a URL you specify here. It will also affect the Home Page if it is set to open the New Tab page, as well as the startup page if set to New Tab page.
+
+          This policy is not available on Windows instances that are not joined to an Active Directory domain.''',

[pastarmovj, 2017/01/19 14:56:21]

Add one more sentence below or above this one. e.g. "If the policy is not set or
left empty the default new tab page is used." It is a MS recommendation for the
policy documentation to always state explicitly the default behavior when the
policy is not set.

[MAD, 2017/01/19 16:13:30]

Done.

+          'label': '''New Tab page URL''',
+        },
+      ],
+    },
+    {
       'name': 'DefaultBrowserSettingEnabled',
       'type': 'main',
       'schema': { 'type': 'boolean' },
       'supported_on': ['chrome.*:11-'],
       'features': {
         'dynamic_refresh': True,
         'per_profile': False,
       },
       'example_value': True,
       'id': 3,
@@ skipping 9240 matching lines @@
       '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)',
     },
     'doc_complex_policies_on_windows': {
       'desc': '''Text pointing the user to a help article for complex policies on Windows''',
       'text': '''encoded as a JSON string, for details see <ph name="COMPLEX_POLICIES_URL">https://www.chromium.org/administrators/complex-policies-on-windows<ex>https://www.chromium.org/administrators/complex-policies-on-windows</ex></ph>''',
     },
   },
   'placeholders': [],
 }