Define a new policy to disable clearing the browsing history from the UI.

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 b6f31f855e688a81646bf797ebdb1abb86ad8f58..30d4181814afa3be7a84e69a60dff751847a79bc 100644
--- a/components/policy/resources/policy_templates.json
+++ b/components/policy/resources/policy_templates.json
@@ -653,14 +653,9 @@
     },
     {
       'name': 'AllowDeletingBrowserHistory',
-      'future': True,
       'type': 'main',
       'schema': { 'type': 'boolean' },
-      # TODO(pamg): Restore the correct 'supported' line when the UI properly
-      # shows that deleting browser history is disabled. Also fix the 'os' line
-      # in policy_test_cases.json.
-      # 'supported_on': ['chrome.*:27-', 'chrome_os:27-'],
-      'supported_on': [],
+      'supported_on': ['chrome.*:57-', 'chrome_os:57-'],
       'features': {
         'dynamic_refresh': True,
         'per_profile': True,
@@ -668,7 +663,7 @@
       'example_value': True,
       'id': 187,
       'caption': '''Enable deleting browser and download history''',
-      'tags': [],
+      'tags': ['local-data-access', 'admin-sharing'],
       'desc': '''Enables deleting browser history and download history in <ph name="PRODUCT_NAME">$<ex>Google Chrome</ex></ph> and prevents users from changing this setting.
 
       Note that even with this policy disabled, the browsing and download history are not guaranteed to be retained: users may be able to edit or delete the history database files directly, and the browser itself may expire or archive any or all history items at any time.