Introduce PrefRegistrySyncable, simplifying PrefServiceSyncable.

chrome/browser/ui/gesture_prefs_observer_factory_aura.cc

Index: chrome/browser/ui/gesture_prefs_observer_factory_aura.cc
diff --git a/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc b/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc
index a8c96811359c985a8ef25d2807db94efeb735026..91290e355643f64fe6c927f7410aec57e93248e2 100644
--- a/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc
+++ b/chrome/browser/ui/gesture_prefs_observer_factory_aura.cc
@@ -8,6 +8,7 @@
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_dependency_manager.h"
@@ -228,134 +229,135 @@ ProfileKeyedService* GesturePrefsObserverFactoryAura::BuildServiceInstanceFor(
 }
 
 void GesturePrefsObserverFactoryAura::RegisterOverscrollPrefs(
-    PrefServiceSyncable* prefs) {
+    PrefRegistrySyncable* registry) {
   const OverscrollPref* overscroll_prefs =
       GesturePrefsObserver::GetOverscrollPrefs();
 
   for (int i = 0; overscroll_prefs[i].pref_name; ++i) {
-    prefs->RegisterDoublePref(
+    registry->RegisterDoublePref(
         overscroll_prefs[i].pref_name,
         content::GetOverscrollConfig(overscroll_prefs[i].config),
-        PrefServiceSyncable::UNSYNCABLE_PREF);
+        PrefRegistrySyncable::UNSYNCABLE_PREF);
   }
 }
 
-void GesturePrefsObserverFactoryAura::RegisterUserPrefs(
-    PrefServiceSyncable* prefs) {
-  prefs->RegisterDoublePref(
+void GesturePrefsObserverFactoryAura::DeprecatedRegisterUserPrefs(
+    PrefService* prefs,
+    PrefRegistrySyncable* registry) {
+  registry->RegisterDoublePref(
       prefs::kFlingAccelerationCurveCoefficient0,
       GestureConfiguration::fling_acceleration_curve_coefficients(0),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kFlingAccelerationCurveCoefficient1,
       GestureConfiguration::fling_acceleration_curve_coefficients(1),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kFlingAccelerationCurveCoefficient2,
       GestureConfiguration::fling_acceleration_curve_coefficients(2),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kFlingAccelerationCurveCoefficient3,
       GestureConfiguration::fling_acceleration_curve_coefficients(3),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterIntegerPref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterIntegerPref(
       prefs::kFlingMaxCancelToDownTimeInMs,
       GestureConfiguration::fling_max_cancel_to_down_time_in_ms(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterIntegerPref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterIntegerPref(
       prefs::kFlingMaxTapGapTimeInMs,
       GestureConfiguration::fling_max_tap_gap_time_in_ms(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kFlingVelocityCap,
       GestureConfiguration::fling_velocity_cap(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kLongPressTimeInSeconds,
       GestureConfiguration::long_press_time_in_seconds(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kSemiLongPressTimeInSeconds,
       GestureConfiguration::semi_long_press_time_in_seconds(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMaxDistanceForTwoFingerTapInPixels,
       GestureConfiguration::max_distance_for_two_finger_tap_in_pixels(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMaxSecondsBetweenDoubleClick,
       GestureConfiguration::max_seconds_between_double_click(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMaxSeparationForGestureTouchesInPixels,
       GestureConfiguration::max_separation_for_gesture_touches_in_pixels(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMaxSwipeDeviationRatio,
       GestureConfiguration::max_swipe_deviation_ratio(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMaxTouchDownDurationInSecondsForClick,
       GestureConfiguration::max_touch_down_duration_in_seconds_for_click(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMaxTouchMoveInPixelsForClick,
       GestureConfiguration::max_touch_move_in_pixels_for_click(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMaxDistanceBetweenTapsForDoubleTap,
       GestureConfiguration::max_distance_between_taps_for_double_tap(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMinDistanceForPinchScrollInPixels,
       GestureConfiguration::min_distance_for_pinch_scroll_in_pixels(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMinFlickSpeedSquared,
       GestureConfiguration::min_flick_speed_squared(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMinPinchUpdateDistanceInPixels,
       GestureConfiguration::min_pinch_update_distance_in_pixels(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMinRailBreakVelocity,
       GestureConfiguration::min_rail_break_velocity(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMinScrollDeltaSquared,
       GestureConfiguration::min_scroll_delta_squared(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMinSwipeSpeed,
       GestureConfiguration::min_swipe_speed(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kMinTouchDownDurationInSecondsForClick,
       GestureConfiguration::min_touch_down_duration_in_seconds_for_click(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterIntegerPref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterIntegerPref(
       prefs::kPointsBufferedForVelocity,
       GestureConfiguration::points_buffered_for_velocity(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kRailBreakProportion,
       GestureConfiguration::rail_break_proportion(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
-  prefs->RegisterDoublePref(
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(
       prefs::kRailStartProportion,
       GestureConfiguration::rail_start_proportion(),
-      PrefServiceSyncable::UNSYNCABLE_PREF);
+      PrefRegistrySyncable::UNSYNCABLE_PREF);
 
   // TODO(rjkroege): Remove this in M29. http://crbug.com/160243.
   const char kTouchScreenFlingAccelerationAdjustment[] =
       "gesture.touchscreen_fling_acceleration_adjustment";
-  prefs->RegisterDoublePref(kTouchScreenFlingAccelerationAdjustment,
-                            0.0,
-                            PrefServiceSyncable::UNSYNCABLE_PREF);
+  registry->RegisterDoublePref(kTouchScreenFlingAccelerationAdjustment,
+                               0.0,
+                               PrefRegistrySyncable::UNSYNCABLE_PREF);
   prefs->ClearPref(kTouchScreenFlingAccelerationAdjustment);

[Mattias Nissler (ping if slow), 2013/02/06 17:53:33]

non-scoring comment: This should be part of migration.

[Jói, 2013/02/07 14:52:32]

Agreed, I think many of the "special" cases we're seeing in RegisterPrefs and
RegisterUserPrefs can be moved to separate MigratePrefs and MigrateUserPrefs
that get called post PrefService construction.  I wonder if there should be more
specific support for migration than the "Register then Clear" or "Register then
Clear then Unregister" combos I'm seeing in various places.

[Mattias Nissler (ping if slow), 2013/02/08 11:26:56]

+1 to adding that migration code path.

Regarding the registration/unregistration, I wouldn't worry too much: What's the
harm in keeping the registrations for deprecated prefs in the regular
RegisterPrefs() code paths? Once the migration code gets removed, we can remove
the registrations as well.

 
-  RegisterOverscrollPrefs(prefs);
+  RegisterOverscrollPrefs(registry);
 }
 
 bool GesturePrefsObserverFactoryAura::ServiceIsCreatedWithProfile() const {