Split the aggregate dictionary of content settings exceptions into per-type dictionaries

components/content_settings/core/browser/content_settings_pref_provider.h

Index: components/content_settings/core/browser/content_settings_pref_provider.h
diff --git a/components/content_settings/core/browser/content_settings_pref_provider.h b/components/content_settings/core/browser/content_settings_pref_provider.h
index 8c26c4d3e774f4865b82af7b53243f566ef8fd01..ec235a9407d9fe4950dcc4fcdc783cedcedbdb9f 100644
--- a/components/content_settings/core/browser/content_settings_pref_provider.h
+++ b/components/content_settings/core/browser/content_settings_pref_provider.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/memory/scoped_vector.h"
 #include "base/prefs/pref_change_registrar.h"
 #include "components/content_settings/core/browser/content_settings_observable_provider.h"
 #include "components/content_settings/core/browser/content_settings_utils.h"
@@ -70,14 +71,20 @@ class PrefProvider : public ObservableProvider {
   // Gains ownership of |clock|.
   void SetClockForTesting(scoped_ptr<base::Clock> clock);
 
-  ContentSettingsPref* content_settings_pref() {
-    return content_settings_pref_.get();
-  }
-
  private:
+  friend class DeadlockCheckerThread;  // For testing.
+
   // Migrate the old media setting into new mic/camera content settings.
   void MigrateObsoleteMediaContentSetting();
 
+  // Migrate the settings from the old aggregate dictionary into the new format.
+  void MigrateAllExceptions();
+
+  // Writes the contents of the old aggregate dictionary preferences into
+  // separate dictionaries for content types. If |syncable_only| is true,
+  // only syncable content types will be written.
+  void WriteSettingsToNewPreferences(bool syncable_only);
+
   // Weak; owned by the Profile and reset in ShutdownOnUIThread.
   PrefService* prefs_;
 
@@ -88,9 +95,56 @@ class PrefProvider : public ObservableProvider {
 
   PrefChangeRegistrar pref_change_registrar_;
 
-  scoped_ptr<ContentSettingsPref> content_settings_pref_;
+  ScopedVector<ContentSettingsPref> content_settings_prefs_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefProvider);
+
+  bool TestAllLocks() const;
+
+  // All functionality regarding reading and writing of preferences has been
+  // moved to |ContentSettingsPref|, which manages one content type per
+  // instance. However, for backward compatibility, we need to be able to write
+  // to the old and deprecated aggregate dictionary preference which maintains
+  // all content types. Therefore, |ContentSettingsPrefProvider| must still
+  // retain some of the functionality of |ContentSettingsPref|. The following
+  // attributes and methods serve this purpose.
+  // TODO(msramek): Remove this migration code after two stable releases.
+  struct ContentSettingsPrefEntry {
+    ContentSettingsPrefEntry(const ContentSettingsPattern primary_pattern,
+                             const ContentSettingsPattern secondary_pattern,
+                             const ResourceIdentifier resource_identifier,
+                             base::Value* value);
+    ContentSettingsPrefEntry(const ContentSettingsPrefEntry& entry);
+    ContentSettingsPrefEntry& operator=(const ContentSettingsPrefEntry& entry);
+    ~ContentSettingsPrefEntry();
+
+    ContentSettingsPattern primary_pattern;
+    ContentSettingsPattern secondary_pattern;
+    ResourceIdentifier resource_identifier;
+    scoped_ptr<base::Value> value;
+  };
+
+  // Stores exceptions read from the old preference before writing them
+  // to the new one.
+  ScopedVector<ContentSettingsPrefEntry>
+      pref_entry_map_[CONTENT_SETTINGS_NUM_TYPES];
+
+  // Clears |pref_entry_map_|.
+  void ClearPrefEntryMap();
+
+  // Guards access to |pref_entry_map_|.
+  mutable base::Lock old_lock_;
+
+  // Indicates whether the old preferences are updated.
+  bool updating_old_preferences_;
+
+  // Called when the old preference changes.
+  void OnOldContentSettingsPatternPairsChanged();
+
+  // Reads the old preference and writes it to |pref_entry_map_|.
+  void ReadContentSettingsFromOldPref();
+
+  base::ThreadChecker thread_checker_;
 };
 
 }  // namespace content_settings