Rewrite DefaultPrefStore for performance

base/prefs/default_pref_store.h

Index: base/prefs/default_pref_store.h
diff --git a/base/prefs/default_pref_store.h b/base/prefs/default_pref_store.h
index 3226cc2ae33c7306bb3fdd2c5d2ebd302ccde90d..e6fdbfacab706f18ce62a2a6ff5ab5f6f80266d3 100644
--- a/base/prefs/default_pref_store.h
+++ b/base/prefs/default_pref_store.h
@@ -8,15 +8,21 @@
 #include <string>
 
 #include "base/prefs/base_prefs_export.h"
-#include "base/prefs/value_map_pref_store.h"
+#include "base/prefs/pref_store.h"
+#include "base/prefs/pref_value_map.h"
 #include "base/values.h"
 
 // This PrefStore keeps track of default preference values set when a
 // preference is registered with the PrefService.
-class BASE_PREFS_EXPORT DefaultPrefStore : public ValueMapPrefStore {
+class BASE_PREFS_EXPORT DefaultPrefStore : public PrefStore {
  public:
+  typedef PrefValueMap::const_iterator const_iterator;
+
   DefaultPrefStore();
 

[battre, 2012/11/07 11:50:49]

nit: // Implementation of PrefStore.

+  virtual ReadResult GetValue(const std::string& key,
+                              const base::Value** result) const OVERRIDE;
+
   // Stores a new |value| for |key|. Assumes ownership of |value|.
   void SetDefaultValue(const std::string& key, Value* value);
 
@@ -27,10 +33,15 @@ class BASE_PREFS_EXPORT DefaultPrefStore : public ValueMapPrefStore {
   // has not been registered.
   base::Value::Type GetType(const std::string& key) const;
 
+  const_iterator begin() const;
+  const_iterator end() const;
+
  protected:
   virtual ~DefaultPrefStore();
 
  private:
+  PrefValueMap prefs_;
+
   DISALLOW_COPY_AND_ASSIGN(DefaultPrefStore);
 };