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

components/content_settings/core/browser/content_settings_policy_provider.h

Index: components/content_settings/core/browser/content_settings_policy_provider.h
diff --git a/components/content_settings/core/browser/content_settings_policy_provider.h b/components/content_settings/core/browser/content_settings_policy_provider.h
index f2058456a24949fde95f63ec1d912f6c53506d9e..03e711ac5bdda02c9bc8b584923bdb20a646efa5 100644
--- a/components/content_settings/core/browser/content_settings_policy_provider.h
+++ b/components/content_settings/core/browser/content_settings_policy_provider.h
@@ -17,6 +17,10 @@
 
 class PrefService;
 
+namespace base {
+class Value;
+}
+
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
@@ -27,6 +31,7 @@ namespace content_settings {
 class PolicyProvider : public ObservableProvider {
  public:
   explicit PolicyProvider(PrefService* prefs);
+  PolicyProvider(PrefService* prefs, bool want_recommended);
   ~PolicyProvider() override;
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
@@ -51,6 +56,10 @@ class PolicyProvider : public ObservableProvider {
 
   static const PrefsForManagedDefaultMapEntry kPrefsForManagedDefault[];
 
+  // Returns the value specified specified by |prev_name| in accordance to
+  // |want_recommended_|.
+  const base::Value* GetWantedPreferenceValue(const char* pref_name) const;
+
   // Reads the policy managed default settings.
   void ReadManagedDefaultSettings();
 
@@ -73,6 +82,10 @@ class PolicyProvider : public ObservableProvider {
 
   PrefService* prefs_;
 
+  // If true then this class handles recommended policy. Otherwise this class
+  // handles mandatory (managed) policy.
+  bool want_recommended_;
+
   PrefChangeRegistrar pref_change_registrar_;
 
   // Used around accesses to the |value_map_| object to guarantee