Make sure key::kEnableWebBasedSignin policy also turns on command line arg

components/policy/resources/policy_templates.json

Index: components/policy/resources/policy_templates.json
diff --git a/components/policy/resources/policy_templates.json b/components/policy/resources/policy_templates.json
index a11123c2e886866e30d67fc146fd727ab2e2f323..17f90ca8c11b2115f20a1de61ad4240eeb4c16d2 100644
--- a/components/policy/resources/policy_templates.json
+++ b/components/policy/resources/policy_templates.json
@@ -1195,16 +1195,20 @@
       'name': 'EnableWebBasedSignin',
       'type': 'main',
       'schema': { 'type': 'boolean' },
-      'supported_on': ['chrome.*:35-'],
+      'supported_on': ['chrome.*:35-42'],
       'features': {
         'dynamic_refresh': False,
         'per_profile': False,
       },
+      'deprecated': True,
       'example_value': False,
       'id': 265,
       'caption': '''Enables the old web-based signin''',
       'desc': '''Enables the old web-based signin flow.
 
+      This setting should no longer be needed as of Chrome 41 and support will be removed entirely in Chrome 43.
+      This setting will be renamed in Chrome 42 as part of the deprecation process.
+
       This setting is useful for enterprise customers who are using SSO solutions that are not compatible with the new inline signin flow yet.
       If you enable this setting, the old web-based signin flow would be used.
       If you disable this setting or leave it not set, the new inline signin flow would be used by default. Users may still enable the old web-based signin flow through the command line flag --enable-web-based-signin.