Change PrefStore::ReadResult to a boolean.

base/prefs/json_pref_store.h

Index: base/prefs/json_pref_store.h
diff --git a/base/prefs/json_pref_store.h b/base/prefs/json_pref_store.h
index 7a75d4cc8fbc834cda6987a3541c144567503505..49dd71ae1814b8dca1405b390c84ff510af89745 100644
--- a/base/prefs/json_pref_store.h
+++ b/base/prefs/json_pref_store.h
@@ -44,16 +44,16 @@ class BASE_PREFS_EXPORT JsonPrefStore
                 base::SequencedTaskRunner* sequenced_task_runner);
 
   // PrefStore overrides:
-  virtual ReadResult GetValue(const std::string& key,
-                              const base::Value** result) const OVERRIDE;
+  virtual bool GetValue(const std::string& key,
+                        const base::Value** result) const OVERRIDE;
   virtual void AddObserver(PrefStore::Observer* observer) OVERRIDE;
   virtual void RemoveObserver(PrefStore::Observer* observer) OVERRIDE;
   virtual size_t NumberOfObservers() const OVERRIDE;
   virtual bool IsInitializationComplete() const OVERRIDE;
 
   // PersistentPrefStore overrides:
-  virtual ReadResult GetMutableValue(const std::string& key,
-                                     base::Value** result) OVERRIDE;
+  virtual bool GetMutableValue(const std::string& key,
+                               base::Value** result) OVERRIDE;
   virtual void SetValue(const std::string& key, base::Value* value) OVERRIDE;
   virtual void SetValueSilently(const std::string& key,
                                 base::Value* value) OVERRIDE;