Add callback list to PrefModelAssociator after sync data is loaded

components/content_settings/core/browser/host_content_settings_map.cc

Index: components/content_settings/core/browser/host_content_settings_map.cc
diff --git a/components/content_settings/core/browser/host_content_settings_map.cc b/components/content_settings/core/browser/host_content_settings_map.cc
index 6e511e9dc0d0c331543a8992fcc80efb9db24812..967ec406c2579a5cefb5da2d3935856ede84d988 100644
--- a/components/content_settings/core/browser/host_content_settings_map.cc
+++ b/components/content_settings/core/browser/host_content_settings_map.cc
@@ -8,6 +8,7 @@
 
 #include <utility>
 
+#include "base/bind.h"
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ -139,15 +140,18 @@ content_settings::PatternPair GetPatternsFromScopingType(
 
 }  // namespace
 
-HostContentSettingsMap::HostContentSettingsMap(PrefService* prefs,
-                                               bool is_incognito_profile,
-                                               bool is_guest_profile)
+HostContentSettingsMap::HostContentSettingsMap(
+    PrefService* prefs,
+    bool is_incognito_profile,
+    bool is_guest_profile,
+    syncable_prefs::PrefServiceSyncable* pref_service)
     :
 #ifndef NDEBUG
       used_from_thread_id_(base::PlatformThread::CurrentId()),
 #endif
       prefs_(prefs),
-      is_off_the_record_(is_incognito_profile || is_guest_profile) {
+      is_off_the_record_(is_incognito_profile || is_guest_profile),
+      pref_service_(pref_service) {
   DCHECK(!(is_incognito_profile && is_guest_profile));
 
   content_settings::PolicyProvider* policy_provider =
@@ -174,6 +178,12 @@ HostContentSettingsMap::HostContentSettingsMap(PrefService* prefs,
   MigrateKeygenSettings();
 
   RecordNumberOfExceptions();
+
+  if (pref_service_) {
+    pref_service_->RegisterMergeDataFinishedCallback(
+        base::Bind(&HostContentSettingsMap::MigrateDomainScopedSettings,
+                   base::Unretained(this)));

[raymes, 2016/06/29 03:50:01]

We should probably use a WeakPtr here instead of base::Unretained(this). That
will ensure that the callback doesn't get called if this object is destroyed.

I think we could also just pass "this", which would keep this object alive until
after the callback has run, but in this case we don't need to keep it alive and
it's probably better not to.

[lshang, 2016/06/30 05:03:36]

Done.

+  }
 }
 
 // static