Add a cache for FillFontFamilyMap.

base/prefs/pref_service.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This provides a way to access the application's current preferences.
 
 // Chromium settings and storage represent user-selected preferences and
 // information and MUST not be extracted, overwritten or modified except
 // through Chromium defined APIs.
 
 #ifndef BASE_PREFS_PREF_SERVICE_H_
 #define BASE_PREFS_PREF_SERVICE_H_
 
 #include <set>
 #include <string>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
+#include "base/containers/scoped_ptr_hash_map.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/prefs/base_prefs_export.h"
 #include "base/prefs/persistent_pref_store.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/values.h"
 
 class PrefNotifier;
 class PrefNotifierImpl;
 class PrefObserver;
 class PrefRegistry;
 class PrefValueStore;
 class PrefStore;
 
 namespace base {
 class FilePath;
 }
 
 namespace subtle {
 class PrefMemberBase;
 class ScopedUserPrefUpdateBase;
 }
 
+// Base class for caches associated with the PrefService.
+class BASE_PREFS_EXPORT PrefServiceCache {
+};
+
 // Base class for PrefServices. You can use the base class to read and
 // interact with preferences, but not to register new preferences; for
 // that see e.g. PrefRegistrySimple.
 //
 // Settings and storage accessed through this class represent
 // user-selected preferences and information and MUST not be
 // extracted, overwritten or modified except through the defined APIs.
 class BASE_PREFS_EXPORT PrefService : public base::NonThreadSafe {
  public:
   enum PrefInitializationStatus {
@@ skipping 209 matching lines @@
   // register all preferences for a class Xyz up front in a static
   // Xyz::RegisterPrefs function, which gets invoked early in the
   // application's start-up, before a PrefService is created.
   //
   // As an example, prefs registration in Chrome is triggered by the
   // functions chrome::RegisterPrefs (for global preferences) and
   // chrome::RegisterProfilePrefs (for user-specific preferences)
   // implemented in chrome/browser/prefs/browser_prefs.cc.
   PrefRegistry* DeprecatedGetPrefRegistry();
 
+  base::ScopedPtrHashMap<const char*, PrefServiceCache>* GetPrefsCaches() {
+    return &prefs_caches_;
+  }
+
  protected:
   // The PrefNotifier handles registering and notifying preference observers.
   // It is created and owned by this PrefService. Subclasses may access it for
   // unit testing.
   scoped_ptr<PrefNotifierImpl> pref_notifier_;
 
   // The PrefValueStore provides prioritized preference values. It is owned by
   // this PrefService. Subclasses may access it for unit testing.
   scoped_ptr<PrefValueStore> pref_value_store_;
 
@@ skipping 63 matching lines @@
   // not need to find or create a Preference object to get the
   // value (GetValue() calls back though the preference service to
   // actually get the value.).
   const base::Value* GetPreferenceValue(const std::string& path) const;
 
   // Local cache of registered Preference objects. The pref_registry_
   // is authoritative with respect to what the types and default values
   // of registered preferences are.
   mutable PreferenceMap prefs_map_;
 
+  // General purpose caches.
+  base::ScopedPtrHashMap<const char*, PrefServiceCache> prefs_caches_;
+
   DISALLOW_COPY_AND_ASSIGN(PrefService);
 };
 
 #endif  // BASE_PREFS_PREF_SERVICE_H_