Pref service: expose all read-only PrefStores through Mojo

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..7fb118445766875c7a4f86ec0faf587932ac8513 100644
--- a/components/prefs/pref_value_store.h
+++ b/components/prefs/pref_value_store.h
@@ -117,7 +117,6 @@ class COMPONENTS_PREFS_EXPORT PrefValueStore {
   // Update the command line PrefStore with |command_line_prefs|.
   void UpdateCommandLinePrefStore(PrefStore* command_line_prefs);
 
- private:
   // PrefStores must be listed here in order from highest to lowest priority.
   //   MANAGED contains all managed preference values that are provided by
   //      mandatory policies (e.g. Windows Group Policy or cloud policy).
@@ -142,6 +141,7 @@ class COMPONENTS_PREFS_EXPORT PrefValueStore {
     PREF_STORE_TYPE_MAX = DEFAULT_STORE
   };
 
+ private:
   // Keeps a PrefStore reference on behalf of the PrefValueStore and monitors
   // the PrefStore for changes, forwarding notifications to PrefValueStore. This
   // indirection is here for the sake of disambiguating notifications from the
@@ -257,4 +257,15 @@ class COMPONENTS_PREFS_EXPORT PrefValueStore {
   DISALLOW_COPY_AND_ASSIGN(PrefValueStore);
 };
 
+namespace std {
+
+template <>
+struct hash<PrefValueStore::PrefStoreType> {
+  size_t operator()(const PrefValueStore::PrefStoreType& type) const {
+    return static_cast<std::size_t>(type);

[Sam McNally, 2017/02/24 04:14:53]

size_t for an enum with a -1?

[tibell, 2017/02/27 00:02:53]

Done.

+  }
+};
+
+}  // namespace std
+
 #endif  // COMPONENTS_PREFS_PREF_VALUE_STORE_H_