Move preference MACs to the protected preference stores.

chrome/browser/prefs/tracked/tracked_preferences_migration.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_PREFS_TRACKED_TRACKED_PREFERENCES_MIGRATION_H_
 #define CHROME_BROWSER_PREFS_TRACKED_TRACKED_PREFERENCES_MIGRATION_H_
 
 #include <set>
 #include <string>
 
 #include "base/callback_forward.h"
+#include "base/memory/scoped_ptr.h"
 
-class InterceptablePrefFilter;
+namespace base {
+class DictionaryValue;
+}  // namespace base
+
+class PrefHashStore;
+
+class TrackedPreferencesMigrationDelegate {

[gab, 2014/06/06 21:55:00]

As mentioned before, I agree that this delegate may be a nice addition to reduce
the number of parameters to SetupTrackedPreferencesMigration.

But since it only has one caller, I don't think it's a necessary cleanup as part
of this CL.

[erikwright (departed), 2014/06/10 20:27:48]

I found it preferable to adding an additional two parameters to the public
method (and many of the private methods).

[gab, 2014/06/11 18:23:55]

Agreed, except that for the sake of simplicity on the core change, I think this
should be done in a follow-up CL.

+ public:
+  virtual ~TrackedPreferencesMigrationDelegate() {}
+
+  typedef base::Callback<void(bool prefs_altered)> InterceptCompletionCallback;
+
+  // A callback to be invoked from FilterOnLoad. It takes ownership of prefs
+  // and may modify them before handing them back to this
+  // InterceptablePrefFilter via |finalize_filter_on_load|.
+  typedef base::Callback<
+      void(const InterceptCompletionCallback& completion_callback,
+           base::DictionaryValue* prefs)> Intercept;
+
+  virtual void CleanPreference(const std::string& key) = 0;
+  virtual void NotifyOnSuccessfulWrite(
+      const base::Closure& on_successful_write) = 0;
+  virtual void InterceptLoadedPreferences(const Intercept& intercept) = 0;
+  virtual PrefHashStore* GetPrefHashStore() = 0;
+};
 
 // Sets up InterceptablePrefFilter::FilterOnLoadInterceptors on
 // |unprotected_pref_filter| and |protected_pref_filter| which prevents each
 // filter from running their on load operations until the interceptors decide to
 // hand the prefs back to them (after migration is complete). |
 // (un)protected_store_cleaner| and
 // |register_on_successful_(un)protected_store_write_callback| are used to do
 // post-migration cleanup tasks. Those should be bound to weak pointers to avoid
 // blocking shutdown. The migration framework is resilient to a failed cleanup
 // (it will simply try again in the next Chrome run).
 void SetupTrackedPreferencesMigration(
     const std::set<std::string>& unprotected_pref_names,
     const std::set<std::string>& protected_pref_names,
-    const base::Callback<void(const std::string& key)>&
-        unprotected_store_cleaner,
-    const base::Callback<void(const std::string& key)>& protected_store_cleaner,
-    const base::Callback<void(const base::Closure&)>&
-        register_on_successful_unprotected_store_write_callback,
-    const base::Callback<void(const base::Closure&)>&
-        register_on_successful_protected_store_write_callback,
-    InterceptablePrefFilter* unprotected_pref_filter,
-    InterceptablePrefFilter* protected_pref_filter);
+    scoped_ptr<TrackedPreferencesMigrationDelegate> unprotected_delegate,
+    scoped_ptr<TrackedPreferencesMigrationDelegate> protected_delegate,
+    scoped_ptr<PrefHashStore> legacy_pref_hash_store);
 
 #endif  // CHROME_BROWSER_PREFS_TRACKED_TRACKED_PREFERENCES_MIGRATION_H_