[Policy Experimental] Add "recommended" policies for URL exceptions.

components/prefs/pref_value_store.h

Index: components/prefs/pref_value_store.h
diff --git a/components/prefs/pref_value_store.h b/components/prefs/pref_value_store.h
index 39b6bf1870ee3fc06e1eb9f53a243284c6109334..a66b059820af6bc6b74db576ba9f9cb2909d0a1e 100644
--- a/components/prefs/pref_value_store.h
+++ b/components/prefs/pref_value_store.h
@@ -81,6 +81,15 @@ class COMPONENTS_PREFS_EXPORT PrefValueStore {
                 base::Value::Type type,
                 const base::Value** out_value) const;
 
+  // Gets the managed value for the given preference name that has the
+  // specified value type. A value stored in the managed PrefStore that has
+  // the matching |name| but a non-matching |type| is silently ignored. Returns
+  // true if a valid value was found. Most callers should use
+  // Preference::GetManagedValue() instead of calling this method directly.
+  bool GetManagedValue(const std::string& name,
+                       base::Value::Type type,
+                       const base::Value** out_value) const;
+
   // Gets the recommended value for the given preference name that has the
   // specified value type. A value stored in the recommended PrefStore that has
   // the matching |name| but a non-matching |type| is silently ignored. Returns