Unwind the fallback admin policy knobs.

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 7891 matching lines @@
       'supported_on': [
         'chrome.*:50-52',
         'chrome_os:50-52',
         'android:50-52',
         'ios:50-52',
       ],
       'features': {
         'dynamic_refresh': True,
         'per_profile': False,
       },
+      'deprecated': True,
       'example_value': 'tls1.1',
       'id': 280,
       'caption': '''Minimum TLS version to fallback to''',
       'tags': ['system-security'],
       'desc': '''Warning: The TLS version fallback will be 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.
 
       When a TLS handshake fails, <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> would previously 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 or if it is set to "tls1.2" then <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> no longer performs this fallback. Note this does not disable support for older TLS versions, only whether <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> will work around buggy servers which cannot negotiate versions correctly.
 
@@ skipping 862 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': [],
 }