Remove RC4 by default.

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 116 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: 309
+#   For your editing convenience: highest ID currently used: 310
 #
 # 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 7602 matching lines @@
 
       When a TLS handshake fails, <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> will retry the connection with a lesser version of TLS in order to work around bugs in HTTPS servers. This setting configures the version at which this fallback process will stop. If a server performs version negotiation correctly (i.e. without breaking the connection) then this setting doesn't apply. Regardless, the resulting connection must still comply with SSLVersionMin.
 
       If this policy is not configured then <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> uses a default minimum version which is TLS 1.0 in <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> 44 and TLS 1.1 in later versions. Note this does not disable support for TLS 1.0, only whether <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> will work around buggy servers which cannot negotiate versions correctly.
 
       Otherwise it may be set to one of the following values: "tls1", "tls1.1" or "tls1.2". If compatibility with a buggy server must be maintained, this may be set to "tls1". This is a stopgap measure and the server should be rapidly fixed.
 
       A setting of "tls1.2" disables all fallback but this may have a significant compatibility impact.''',
     },
     {
+      'name': 'RC4Enabled',
+      'type': 'main',
+      'schema': {
+        'type': 'boolean',
+      },
+      'supported_on': [
+        'chrome.*:48-52',
+        'chrome_os:48-52',
+        'android:48-52',
+        'ios:48-52',
+      ],
+      'features': {
+        'dynamic_refresh': True,
+        'per_profile': False,
+      },
+      'example_value': False,
+      'id': 310,
+      'caption': '''Whether RC4 cipher suites in TLS are enabled''',
+      'tags': ['system-security'],
+      'desc': '''Warning: RC4 will be completely removed from <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> after version 52 (around September 2016) and this policy will stop working then.
+
+      If the policy is not set, or is set to false, then RC4 cipher suites in TLS will not be enabled. Otherwise it may be set to true to retain compatibility with an outdated server. This is a stopgap measure and the server should be reconfigured.''',
+    },
+    {
       'name': 'ContextualSearchEnabled',
       'type': 'main',
       'schema': { 'type': 'boolean' },
       'supported_on': [
         'android:40-',
       ],
       'features': {
         'dynamic_refresh': True,
         'per_profile': True,
       },
@@ skipping 324 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': [],
 }