[Sync] Add location parameter to SyncChange in Sync API.

SyncChanges now require the location they were created as a parameter. This
is then used in the case that the change violates and invariant. We display
the location and type of erroneous change in about:sync, in addition to
disabling the offending datatype.

TBR=kalman@chromium.org, mnissler@chromium.org, isherman@chromium.org
BUG=135108
TEST=unit_tests


Review URL: https://chromiumcodereview.appspot.com/10766016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@145993 0039d316-1c4b-4281-b951-d872f2087c98

19 files changed, 193 insertions, 90 deletions

diff --git a/chrome/browser/extensions/app_notification_manager.cc b/chrome/browser/extensions/app_notification_manager.cc
index 6b1566a..fd40bda 100644
--- a/chrome/browser/extensions/app_notification_manager.cc
+++ b/chrome/browser/extensions/app_notification_manager.cc
@@ -338,7 +338,9 @@ syncer::SyncError AppNotificationManager::MergeDataAndStartSyncing(
   for (SyncDataMap::const_iterator iter = local_data_map.begin();
       iter != local_data_map.end(); ++iter) {
     new_changes.push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_ADD, iter->second));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_ADD,
+                           iter->second));
   }
 
   syncer::SyncError error;
@@ -494,7 +496,9 @@ void AppNotificationManager::SyncAddChange(const AppNotification& notif) {
   syncer::SyncChangeList changes;
   syncer::SyncData sync_data = CreateSyncDataFromNotification(notif);
   changes.push_back(
-      syncer::SyncChange(syncer::SyncChange::ACTION_ADD, sync_data));
+      syncer::SyncChange(FROM_HERE,
+                         syncer::SyncChange::ACTION_ADD,
+                         sync_data));
   sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
 }
 
@@ -509,7 +513,9 @@ void AppNotificationManager::SyncRemoveChange(const AppNotification& notif) {
   syncer::SyncChangeList changes;
   syncer::SyncData sync_data = CreateSyncDataFromNotification(notif);
   changes.push_back(
-      syncer::SyncChange(syncer::SyncChange::ACTION_DELETE, sync_data));
+      syncer::SyncChange(FROM_HERE,
+                         syncer::SyncChange::ACTION_DELETE,
+                         sync_data));
   sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
 }
 
@@ -529,6 +535,7 @@ void AppNotificationManager::SyncClearAllChange(
     if (notif.is_local())
       continue;
     changes.push_back(syncer::SyncChange(
+        FROM_HERE,
         syncer::SyncChange::ACTION_DELETE,
         CreateSyncDataFromNotification(notif)));
   }
diff --git a/chrome/browser/extensions/app_notification_manager_sync_unittest.cc b/chrome/browser/extensions/app_notification_manager_sync_unittest.cc
index f032b82..9b58a9a 100644
--- a/chrome/browser/extensions/app_notification_manager_sync_unittest.cc
+++ b/chrome/browser/extensions/app_notification_manager_sync_unittest.cc
@@ -206,7 +206,9 @@ class AppNotificationManagerSyncTest : public testing::Test {
     // Take control of notif to clean it up after we create data out of it.
     scoped_ptr<AppNotification> scoped_notif(notif);
     return syncer::SyncChange(
-        type, AppNotificationManager::CreateSyncDataFromNotification(*notif));
+        FROM_HERE,
+        type,
+        AppNotificationManager::CreateSyncDataFromNotification(*notif));
   }
 
   void AssertSyncChange(const syncer::SyncChange& change,
diff --git a/chrome/browser/extensions/app_sync_bundle.cc b/chrome/browser/extensions/app_sync_bundle.cc
index af26282..e5cc6a1 100644
--- a/chrome/browser/extensions/app_sync_bundle.cc
+++ b/chrome/browser/extensions/app_sync_bundle.cc
@@ -60,10 +60,14 @@ void AppSyncBundle::ProcessDeletion(std::string extension_id,
 syncer::SyncChange AppSyncBundle::CreateSyncChange(
     const syncer::SyncData& sync_data) {
   if (HasExtensionId(sync_data.GetTag())) {
-    return syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data);
+    return syncer::SyncChange(FROM_HERE,
+                              syncer::SyncChange::ACTION_UPDATE,
+                              sync_data);
   } else {
     AddApp(sync_data.GetTag());
-    return syncer::SyncChange(syncer::SyncChange::ACTION_ADD, sync_data);
+    return syncer::SyncChange(FROM_HERE,
+                              syncer::SyncChange::ACTION_ADD,
+                              sync_data);
   }
 }
 
diff --git a/chrome/browser/extensions/app_sync_data.cc b/chrome/browser/extensions/app_sync_data.cc
index babdedc..d4d24b5 100644
--- a/chrome/browser/extensions/app_sync_data.cc
+++ b/chrome/browser/extensions/app_sync_data.cc
@@ -52,7 +52,7 @@ syncer::SyncData AppSyncData::GetSyncData() const {
 
 syncer::SyncChange AppSyncData::GetSyncChange(
     syncer::SyncChange::SyncChangeType change_type) const {
-  return syncer::SyncChange(change_type, GetSyncData());
+  return syncer::SyncChange(FROM_HERE, change_type, GetSyncData());
 }
 
 void AppSyncData::PopulateAppSpecifics(sync_pb::AppSpecifics* specifics) const {
diff --git a/chrome/browser/extensions/extension_service_unittest.cc b/chrome/browser/extensions/extension_service_unittest.cc
index 219e011..5d51fbf 100644
--- a/chrome/browser/extensions/extension_service_unittest.cc
+++ b/chrome/browser/extensions/extension_service_unittest.cc
@@ -4360,7 +4360,9 @@ TEST_F(ExtensionServiceTest, SyncForUninstalledExternalExtension) {
 
   syncer::SyncData sync_data =
       syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-  syncer::SyncChange sync_change(syncer::SyncChange::ACTION_UPDATE, sync_data);
+  syncer::SyncChange sync_change(FROM_HERE,
+                                 syncer::SyncChange::ACTION_UPDATE,
+                                 sync_data);
   syncer::SyncChangeList list(1);
   list[0] = sync_change;
 
@@ -4493,7 +4495,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataUninstall) {
   ext_specifics->set_version("1.0");
   syncer::SyncData sync_data =
       syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-  syncer::SyncChange sync_change(syncer::SyncChange::ACTION_DELETE, sync_data);
+  syncer::SyncChange sync_change(FROM_HERE,
+                                 syncer::SyncChange::ACTION_DELETE,
+                                 sync_data);
   syncer::SyncChangeList list(1);
   list[0] = sync_change;
 
@@ -4535,8 +4539,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataWrongType) {
     extension_specifics->set_enabled(true);
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_DELETE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_DELETE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
 
@@ -4549,8 +4554,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataWrongType) {
     extension_specifics->set_enabled(false);
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_UPDATE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_UPDATE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
 
@@ -4583,8 +4589,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataSettings) {
   {
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_UPDATE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_UPDATE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
     service_->ProcessSyncChanges(FROM_HERE, list);
@@ -4597,8 +4604,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataSettings) {
     ext_specifics->set_incognito_enabled(true);
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_UPDATE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_UPDATE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
     service_->ProcessSyncChanges(FROM_HERE, list);
@@ -4611,8 +4619,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataSettings) {
     ext_specifics->set_incognito_enabled(true);
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_UPDATE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_UPDATE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
     service_->ProcessSyncChanges(FROM_HERE, list);
@@ -4645,7 +4654,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataTerminatedExtension) {
   ext_specifics->set_incognito_enabled(true);
   syncer::SyncData sync_data =
       syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-  syncer::SyncChange sync_change(syncer::SyncChange::ACTION_UPDATE, sync_data);
+  syncer::SyncChange sync_change(FROM_HERE,
+                                 syncer::SyncChange::ACTION_UPDATE,
+                                 sync_data);
   syncer::SyncChangeList list(1);
   list[0] = sync_change;
 
@@ -4679,8 +4690,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataVersionCheck) {
         service_->GetInstalledExtension(good_crx)->version()->GetString());
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_UPDATE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_UPDATE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
 
@@ -4695,8 +4707,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataVersionCheck) {
     ext_specifics->set_version("0.0.0.0");
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_UPDATE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_UPDATE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
 
@@ -4709,8 +4722,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataVersionCheck) {
     ext_specifics->set_version("9.9.9.9");
     syncer::SyncData sync_data =
         syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-    syncer::SyncChange sync_change(
-        syncer::SyncChange::ACTION_UPDATE, sync_data);
+    syncer::SyncChange sync_change(FROM_HERE,
+                                   syncer::SyncChange::ACTION_UPDATE,
+                                   sync_data);
     syncer::SyncChangeList list(1);
     list[0] = sync_change;
 
@@ -4739,7 +4753,9 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataNotInstalled) {
   ext_specifics->set_version("1.2.3.4");
   syncer::SyncData sync_data =
       syncer::SyncData::CreateLocalData(good_crx, "Name", specifics);
-  syncer::SyncChange sync_change(syncer::SyncChange::ACTION_UPDATE, sync_data);
+  syncer::SyncChange sync_change(FROM_HERE,
+                                 syncer::SyncChange::ACTION_UPDATE,
+                                 sync_data);
   syncer::SyncChangeList list(1);
   list[0] = sync_change;
 
diff --git a/chrome/browser/extensions/extension_sync_bundle.cc b/chrome/browser/extensions/extension_sync_bundle.cc
index 91c71bb..a9db2be 100644
--- a/chrome/browser/extensions/extension_sync_bundle.cc
+++ b/chrome/browser/extensions/extension_sync_bundle.cc
@@ -59,10 +59,14 @@ void ExtensionSyncBundle::ProcessDeletion(
 syncer::SyncChange ExtensionSyncBundle::CreateSyncChange(
     const syncer::SyncData& sync_data) {
   if (HasExtensionId(sync_data.GetTag())) {
-    return syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data);
+    return syncer::SyncChange(FROM_HERE,
+                              syncer::SyncChange::ACTION_UPDATE,
+                              sync_data);
   } else {
     AddExtension(sync_data.GetTag());
-    return syncer::SyncChange(syncer::SyncChange::ACTION_ADD, sync_data);
+    return syncer::SyncChange(FROM_HERE,
+                              syncer::SyncChange::ACTION_ADD,
+                              sync_data);
   }
 }
 
diff --git a/chrome/browser/extensions/extension_sync_data.cc b/chrome/browser/extensions/extension_sync_data.cc
index d395b19..f9982ab 100644
--- a/chrome/browser/extensions/extension_sync_data.cc
+++ b/chrome/browser/extensions/extension_sync_data.cc
@@ -58,7 +58,7 @@ syncer::SyncData ExtensionSyncData::GetSyncData() const {
 
 syncer::SyncChange ExtensionSyncData::GetSyncChange(
     syncer::SyncChange::SyncChangeType change_type) const {
-  return syncer::SyncChange(change_type, GetSyncData());
+  return syncer::SyncChange(FROM_HERE, change_type, GetSyncData());
 }
 
 void ExtensionSyncData::PopulateExtensionSpecifics(
diff --git a/chrome/browser/extensions/settings/settings_sync_util.cc b/chrome/browser/extensions/settings/settings_sync_util.cc
index c3e46b7..5c6c28a 100644
--- a/chrome/browser/extensions/settings/settings_sync_util.cc
+++ b/chrome/browser/extensions/settings/settings_sync_util.cc
@@ -78,6 +78,7 @@ syncer::SyncChange CreateAdd(
     const Value& value,
     syncer::ModelType type) {
   return syncer::SyncChange(
+      FROM_HERE,
       syncer::SyncChange::ACTION_ADD,
       CreateData(extension_id, key, value, type));
 }
@@ -88,6 +89,7 @@ syncer::SyncChange CreateUpdate(
     const Value& value,
     syncer::ModelType type) {
   return syncer::SyncChange(
+      FROM_HERE,
       syncer::SyncChange::ACTION_UPDATE,
       CreateData(extension_id, key, value, type));
 }
@@ -98,6 +100,7 @@ syncer::SyncChange CreateDelete(
     syncer::ModelType type) {
   DictionaryValue no_value;
   return syncer::SyncChange(
+      FROM_HERE,
       syncer::SyncChange::ACTION_DELETE,
       CreateData(extension_id, key, no_value, type));
 }
diff --git a/chrome/browser/prefs/pref_model_associator.cc b/chrome/browser/prefs/pref_model_associator.cc
index 0ed80e1..5edab25 100644
--- a/chrome/browser/prefs/pref_model_associator.cc
+++ b/chrome/browser/prefs/pref_model_associator.cc
@@ -80,7 +80,9 @@ void PrefModelAssociator::InitPrefAndAssociate(
         return;
       }
       sync_changes->push_back(
-          syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data));
+          syncer::SyncChange(FROM_HERE,
+                             syncer::SyncChange::ACTION_UPDATE,
+                             sync_data));
     }
   } else if (pref->IsUserControlled()) {
     // The server does not know about this preference and should be added
@@ -91,7 +93,9 @@ void PrefModelAssociator::InitPrefAndAssociate(
       return;
     }
     sync_changes->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_ADD, sync_data));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_ADD,
+                           sync_data));
   } else {
     // This pref does not have a sync value but also does not have a user
     // controlled value (either it's a default value or it's policy controlled,
@@ -428,7 +432,9 @@ void PrefModelAssociator::ProcessPrefChange(const std::string& name) {
       return;
     }
     changes.push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_UPDATE,
+                           sync_data));
   }
 
   syncer::SyncError error =
diff --git a/chrome/browser/search_engines/template_url_service.cc b/chrome/browser/search_engines/template_url_service.cc
index 9b691252..10e0c70 100644
--- a/chrome/browser/search_engines/template_url_service.cc
+++ b/chrome/browser/search_engines/template_url_service.cc
@@ -1106,7 +1106,8 @@ syncer::SyncError TemplateURLService::MergeDataAndStartSyncing(
       // preprocessing in TemplateURLService's loading code). Ignore it and send
       // an ACTION_DELETE up to the server.
       new_changes.push_back(
-          syncer::SyncChange(syncer::SyncChange::ACTION_DELETE,
+          syncer::SyncChange(FROM_HERE,
+                             syncer::SyncChange::ACTION_DELETE,
                              iter->second));
       continue;
     }
@@ -1128,8 +1129,9 @@ syncer::SyncError TemplateURLService::MergeDataAndStartSyncing(
         // Otherwise, we know we have newer data, so update Sync with our
         // data fields.
         new_changes.push_back(
-            syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE,
-            local_data_map[local_turl->sync_guid()]));
+            syncer::SyncChange(FROM_HERE,
+                               syncer::SyncChange::ACTION_UPDATE,
+                               local_data_map[local_turl->sync_guid()]));
       }
       local_data_map.erase(iter->first);
     } else {
@@ -1171,7 +1173,9 @@ syncer::SyncError TemplateURLService::MergeDataAndStartSyncing(
   for (SyncDataMap::const_iterator iter = local_data_map.begin();
       iter != local_data_map.end(); ++iter) {
     new_changes.push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_ADD, iter->second));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_ADD,
+                           iter->second));
   }
 
   // Do some post-processing on the change list to ensure that we are sending
@@ -1199,6 +1203,7 @@ void TemplateURLService::StopSyncing(syncer::ModelType type) {
 }
 
 void TemplateURLService::ProcessTemplateURLChange(
+    const tracked_objects::Location& from_here,
     const TemplateURL* turl,
     syncer::SyncChange::SyncChangeType type) {
   DCHECK_NE(type, syncer::SyncChange::ACTION_INVALID);
@@ -1223,7 +1228,9 @@ void TemplateURLService::ProcessTemplateURLChange(
   syncer::SyncChangeList changes;
 
   syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*turl);
-  changes.push_back(syncer::SyncChange(type, sync_data));
+  changes.push_back(syncer::SyncChange(from_here,
+                                       type,
+                                       sync_data));
 
   sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
 }
@@ -1268,7 +1275,9 @@ TemplateURL* TemplateURLService::CreateTemplateURLFromTemplateURLAndSyncData(
   // delete this data off the server.
   if (specifics.url().empty() || specifics.sync_guid().empty()) {
     change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_DELETE, sync_data));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_DELETE,
+                           sync_data));
     return NULL;
   }
 
@@ -1311,7 +1320,9 @@ TemplateURL* TemplateURLService::CreateTemplateURLFromTemplateURLAndSyncData(
       turl->ResetKeywordIfNecessary(true);
     syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*turl);
     change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_UPDATE,
+                           sync_data));
   } else if (turl->IsGoogleSearchURLWithReplaceableKeyword()) {
     if (!existing_turl) {
       // We're adding a new TemplateURL that uses the Google base URL, so set
@@ -1767,7 +1778,9 @@ bool TemplateURLService::UpdateNoNotify(
     service_->UpdateKeyword(existing_turl->data());
 
   // Inform sync of the update.
-  ProcessTemplateURLChange(existing_turl, syncer::SyncChange::ACTION_UPDATE);
+  ProcessTemplateURLChange(FROM_HERE,
+                           existing_turl,
+                           syncer::SyncChange::ACTION_UPDATE);
 
   if (default_search_provider_ == existing_turl) {
     bool success = SetDefaultSearchProviderNoNotify(existing_turl);
@@ -2098,7 +2111,9 @@ bool TemplateURLService::SetDefaultSearchProviderNoNotify(TemplateURL* url) {
 
   // Inform sync the change to the show_in_default_list flag.
   if (url)
-    ProcessTemplateURLChange(url, syncer::SyncChange::ACTION_UPDATE);
+    ProcessTemplateURLChange(FROM_HERE,
+                             url,
+                             syncer::SyncChange::ACTION_UPDATE);
   return true;
 }
 
@@ -2147,7 +2162,9 @@ bool TemplateURLService::AddNoNotify(TemplateURL* template_url,
 
     // Inform sync of the addition. Note that this will assign a GUID to
     // template_url and add it to the guid_to_template_map_.
-    ProcessTemplateURLChange(template_url, syncer::SyncChange::ACTION_ADD);
+    ProcessTemplateURLChange(FROM_HERE,
+                             template_url,
+                             syncer::SyncChange::ACTION_ADD);
   }
 
   return true;
@@ -2177,7 +2194,9 @@ void TemplateURLService::RemoveNoNotify(TemplateURL* template_url) {
     service_->RemoveKeyword(template_url->id());
 
   // Inform sync of the deletion.
-  ProcessTemplateURLChange(template_url, syncer::SyncChange::ACTION_DELETE);
+  ProcessTemplateURLChange(FROM_HERE,
+                           template_url,
+                           syncer::SyncChange::ACTION_DELETE);
 
   if (profile_) {
     content::Source<Profile> source(profile_);
@@ -2307,8 +2326,9 @@ bool TemplateURLService::ResolveSyncKeywordConflict(
   const bool can_replace_local = CanReplace(local_turl);
   if (CanReplace(sync_turl) && (local_is_better || !can_replace_local)) {
     syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*sync_turl);
-    change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_DELETE, sync_data));
+    change_list->push_back(syncer::SyncChange(FROM_HERE,
+                                              syncer::SyncChange::ACTION_DELETE,
+                                              sync_data));
     return false;
   }
   if (can_replace_local) {
@@ -2321,7 +2341,9 @@ bool TemplateURLService::ResolveSyncKeywordConflict(
     // PruneSyncChanges() will prune out the ACTION_DELETE we create here.
     syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*local_turl);
     change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_DELETE, sync_data));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_DELETE,
+                           sync_data));
     Remove(local_turl);
   } else if (local_is_better) {
     string16 new_keyword = UniquifyKeyword(*sync_turl, false);
@@ -2330,8 +2352,9 @@ bool TemplateURLService::ResolveSyncKeywordConflict(
     // If we update the cloud TURL, we need to push an update back to sync
     // informing it that something has changed.
     syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*sync_turl);
-    change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data));
+    change_list->push_back(syncer::SyncChange(FROM_HERE,
+                                              syncer::SyncChange::ACTION_UPDATE,
+                                              sync_data));
   } else {
     string16 new_keyword = UniquifyKeyword(*local_turl, false);
     TemplateURLData data(local_turl->data());
@@ -2349,8 +2372,9 @@ bool TemplateURLService::ResolveSyncKeywordConflict(
     // caller will later generate; but in this case, PruneSyncChanges() will
     // prune out the ACTION_UPDATE we create here.
     syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*local_turl);
-    change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data));
+    change_list->push_back(syncer::SyncChange(FROM_HERE,
+                                              syncer::SyncChange::ACTION_UPDATE,
+                                              sync_data));
   }
   return true;
 }
@@ -2384,8 +2408,9 @@ void TemplateURLService::MergeSyncAndLocalURLDuplicates(
     // See comments in ResolveSyncKeywordConflict() regarding generating an
     // ACTION_DELETE manually since Remove() won't do it.
     syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*local_turl);
-    change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_DELETE, sync_data));
+    change_list->push_back(syncer::SyncChange(FROM_HERE,
+                                              syncer::SyncChange::ACTION_DELETE,
+                                              sync_data));
     Remove(local_turl);
 
     // Force the local ID to kInvalidTemplateURLID so we can add it.
@@ -2400,8 +2425,9 @@ void TemplateURLService::MergeSyncAndLocalURLDuplicates(
     // having the same GUID.
     ResetTemplateURLGUID(local_turl, sync_turl->sync_guid());
     syncer::SyncData sync_data = CreateSyncDataFromTemplateURL(*local_turl);
-    change_list->push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE, sync_data));
+    change_list->push_back(syncer::SyncChange(FROM_HERE,
+                                              syncer::SyncChange::ACTION_UPDATE,
+                                              sync_data));
   }
 }
 
diff --git a/chrome/browser/search_engines/template_url_service.h b/chrome/browser/search_engines/template_url_service.h
index 5976224..e7472d1 100644
--- a/chrome/browser/search_engines/template_url_service.h
+++ b/chrome/browser/search_engines/template_url_service.h
@@ -292,7 +292,8 @@ class TemplateURLService : public WebDataServiceConsumer,
   // This may send a new SyncChange to the cloud. If our model has not yet been
   // associated with Sync, or if this is triggered by a Sync change, then this
   // does nothing.
-  void ProcessTemplateURLChange(const TemplateURL* turl,
+  void ProcessTemplateURLChange(const tracked_objects::Location& from_here,
+                                const TemplateURL* turl,
                                 syncer::SyncChange::SyncChangeType type);
 
   Profile* profile() const { return profile_; }
diff --git a/chrome/browser/search_engines/template_url_service_sync_unittest.cc b/chrome/browser/search_engines/template_url_service_sync_unittest.cc
index 7a09956..fd034ee 100644
--- a/chrome/browser/search_engines/template_url_service_sync_unittest.cc
+++ b/chrome/browser/search_engines/template_url_service_sync_unittest.cc
@@ -331,7 +331,9 @@ syncer::SyncChange TemplateURLServiceSyncTest::CreateTestSyncChange(
   // We take control of the TemplateURL so make sure it's cleaned up after
   // we create data out of it.
   scoped_ptr<TemplateURL> scoped_turl(turl);
-  return syncer::SyncChange(type,
+  return syncer::SyncChange(
+      FROM_HERE,
+      type,
       TemplateURLService::CreateSyncDataFromTemplateURL(*scoped_turl));
 }
 
diff --git a/chrome/browser/sync/glue/generic_change_processor.cc b/chrome/browser/sync/glue/generic_change_processor.cc
index 006db90..6f8c7aab 100644
--- a/chrome/browser/sync/glue/generic_change_processor.cc
+++ b/chrome/browser/sync/glue/generic_change_processor.cc
@@ -49,6 +49,7 @@ void GenericChangeProcessor::ApplyChangesFromSyncModel(
     if (it->action == syncer::ChangeRecord::ACTION_DELETE) {
       syncer_changes_.push_back(
           syncer::SyncChange(
+              FROM_HERE,
               syncer::SyncChange::ACTION_DELETE,
               syncer::SyncData::CreateRemoteData(it->id, it->specifics)));
     } else {
@@ -65,9 +66,11 @@ void GenericChangeProcessor::ApplyChangesFromSyncModel(
         return;
       }
       syncer_changes_.push_back(
-          syncer::SyncChange(action,
-                     syncer::SyncData::CreateRemoteData(
-                         it->id, read_node.GetEntitySpecifics())));
+          syncer::SyncChange(
+              FROM_HERE,
+              action,
+              syncer::SyncData::CreateRemoteData(
+                  it->id, read_node.GetEntitySpecifics())));
     }
   }
 }
diff --git a/chrome/browser/webdata/autocomplete_syncable_service.cc b/chrome/browser/webdata/autocomplete_syncable_service.cc
index 9992ba7..a28668a 100644
--- a/chrome/browser/webdata/autocomplete_syncable_service.cc
+++ b/chrome/browser/webdata/autocomplete_syncable_service.cc
@@ -157,8 +157,9 @@ syncer::SyncError AutocompleteSyncableService::MergeDataAndStartSyncing(
   for (AutocompleteEntryMap::iterator i = new_db_entries.begin();
        i != new_db_entries.end(); ++i) {
     new_changes.push_back(
-        syncer::SyncChange(
-            i->second.first, CreateSyncData(*(i->second.second))));
+        syncer::SyncChange(FROM_HERE,
+                           i->second.first,
+                           CreateSyncData(*(i->second.second))));
   }
 
   if (ShouldCullSyncedData()) {
@@ -415,16 +416,18 @@ void AutocompleteSyncableService::ActOnChanges(
            (change->type() == AutofillChange::ADD) ?
             syncer::SyncChange::ACTION_ADD :
             syncer::SyncChange::ACTION_UPDATE;
-        new_changes.push_back(syncer::SyncChange(change_type,
-                                         CreateSyncData(entry)));
+        new_changes.push_back(syncer::SyncChange(FROM_HERE,
+                                                 change_type,
+                                                 CreateSyncData(entry)));
         break;
       }
       case AutofillChange::REMOVE: {
         std::vector<base::Time> timestamps;
         AutofillEntry entry(change->key(), timestamps);
         new_changes.push_back(
-            syncer::SyncChange(syncer::SyncChange::ACTION_DELETE,
-                              CreateSyncData(entry)));
+            syncer::SyncChange(FROM_HERE,
+                               syncer::SyncChange::ACTION_DELETE,
+                               CreateSyncData(entry)));
         break;
       }
       default:
diff --git a/chrome/browser/webdata/autofill_profile_syncable_service.cc b/chrome/browser/webdata/autofill_profile_syncable_service.cc
index 1eed62e..48291f5 100644
--- a/chrome/browser/webdata/autofill_profile_syncable_service.cc
+++ b/chrome/browser/webdata/autofill_profile_syncable_service.cc
@@ -140,15 +140,17 @@ syncer::SyncError AutofillProfileSyncableService::MergeDataAndStartSyncing(
   for (GUIDToProfileMap::iterator i = remaining_profiles.begin();
        i != remaining_profiles.end(); ++i) {
     new_changes.push_back(
-        syncer::SyncChange(
-            syncer::SyncChange::ACTION_ADD, CreateData(*(i->second))));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_ADD,
+                           CreateData(*(i->second))));
     profiles_map_[i->first] = i->second;
   }
 
   for (size_t i = 0; i < bundle.profiles_to_sync_back.size(); ++i) {
     new_changes.push_back(
-        syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE,
-                   CreateData(*(bundle.profiles_to_sync_back[i]))));
+        syncer::SyncChange(FROM_HERE,
+                           syncer::SyncChange::ACTION_UPDATE,
+                           CreateData(*(bundle.profiles_to_sync_back[i]))));
   }
 
   syncer::SyncError error;
@@ -434,8 +436,9 @@ void AutofillProfileSyncableService::ActOnChange(
   switch (change.type()) {
     case AutofillProfileChange::ADD:
       new_changes.push_back(
-          syncer::SyncChange(
-              syncer::SyncChange::ACTION_ADD, CreateData(*(change.profile()))));
+          syncer::SyncChange(FROM_HERE,
+                             syncer::SyncChange::ACTION_ADD,
+                             CreateData(*(change.profile()))));
       DCHECK(profiles_map_.find(change.profile()->guid()) ==
              profiles_map_.end());
       profiles_.push_back(new AutofillProfile(*(change.profile())));
@@ -447,14 +450,16 @@ void AutofillProfileSyncableService::ActOnChange(
       DCHECK(it != profiles_map_.end());
       *(it->second) = *(change.profile());
       new_changes.push_back(
-          syncer::SyncChange(syncer::SyncChange::ACTION_UPDATE,
-                     CreateData(*(change.profile()))));
+          syncer::SyncChange(FROM_HERE,
+                             syncer::SyncChange::ACTION_UPDATE,
+                             CreateData(*(change.profile()))));
       break;
     }
     case AutofillProfileChange::REMOVE: {
       AutofillProfile empty_profile(change.key());
       new_changes.push_back(
-          syncer::SyncChange(syncer::SyncChange::ACTION_DELETE,
+          syncer::SyncChange(FROM_HERE,
+                             syncer::SyncChange::ACTION_DELETE,
                              CreateData(empty_profile)));
       profiles_map_.erase(change.key());
       break;
diff --git a/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc b/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc
index 09088e7..5ffa190 100644
--- a/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc
+++ b/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc
@@ -145,9 +145,10 @@ TEST_F(AutofillProfileSyncableServiceTest, MergeDataAndStartSyncing) {
 
   syncer::SyncChangeList expected_change_list;
   expected_change_list.push_back(
-      syncer::SyncChange(syncer::SyncChange::ACTION_ADD,
-                 AutofillProfileSyncableService::CreateData(
-                     (*profiles_from_web_db.front()))));
+      syncer::SyncChange(FROM_HERE,
+                         syncer::SyncChange::ACTION_ADD,
+                         AutofillProfileSyncableService::CreateData(
+                             (*profiles_from_web_db.front()))));
 
   AutofillProfileSyncableService::DataBundle expected_bundle;
   expected_bundle.profiles_to_add.push_back(&profile1);
@@ -227,12 +228,15 @@ TEST_F(AutofillProfileSyncableServiceTest, ProcessSyncChanges) {
   AutofillProfile profile(guid_synced);
   profile.SetInfo(NAME_FIRST, UTF8ToUTF16("Jane"));
   change_list.push_back(
-      syncer::SyncChange(syncer::SyncChange::ACTION_ADD,
-      AutofillProfileSyncableService::CreateData(profile)));
+      syncer::SyncChange(FROM_HERE,
+                         syncer::SyncChange::ACTION_ADD,
+                         AutofillProfileSyncableService::CreateData(profile)));
   AutofillProfile empty_profile(guid_present);
   change_list.push_back(
-      syncer::SyncChange(syncer::SyncChange::ACTION_DELETE,
-                 AutofillProfileSyncableService::CreateData(empty_profile)));
+      syncer::SyncChange(
+          FROM_HERE,
+          syncer::SyncChange::ACTION_DELETE,
+          AutofillProfileSyncableService::CreateData(empty_profile)));
 
   AutofillProfileSyncableService::DataBundle expected_bundle;
   expected_bundle.profiles_to_delete.push_back(guid_present);
diff --git a/sync/api/sync_change.cc b/sync/api/sync_change.cc
index 64da5b7..ee1cdea 100644
--- a/sync/api/sync_change.cc
+++ b/sync/api/sync_change.cc
@@ -11,8 +11,12 @@ namespace syncer {
 SyncChange::SyncChange() : change_type_(ACTION_INVALID) {
 }
 
-SyncChange::SyncChange(SyncChangeType change_type, const SyncData& sync_data)
-    : change_type_(change_type),
+SyncChange::SyncChange(
+    const tracked_objects::Location& from_here,
+    SyncChangeType change_type,
+    const SyncData& sync_data)
+    : location_(from_here),
+      change_type_(change_type),
       sync_data_(sync_data) {
   DCHECK(IsValid());
 }
@@ -66,8 +70,9 @@ std::string SyncChange::ChangeTypeToString(SyncChangeType change_type) {
 }
 
 std::string SyncChange::ToString() const {
-  return "{ changeType: " + ChangeTypeToString(change_type_) +
-      ", syncData: " + sync_data_.ToString() + "}";
+  return "{ " + location_.ToString() + ", changeType: " +
+      ChangeTypeToString(change_type_) + ", syncData: " +
+      sync_data_.ToString() + "}";
 }
 
 void PrintTo(const SyncChange& sync_change, std::ostream* os) {
diff --git a/sync/api/sync_change.h b/sync/api/sync_change.h
index 63a03d9..3cfb1d5 100644
--- a/sync/api/sync_change.h
+++ b/sync/api/sync_change.h
@@ -10,6 +10,7 @@
 #include <string>
 #include <vector>
 
+#include "base/location.h"
 #include "sync/api/sync_data.h"
 
 namespace syncer {
@@ -31,7 +32,10 @@ class SyncChange {
   // Default constructor creates an invalid change.
   SyncChange();
   // Create a new change with the specified sync data.
-  SyncChange(SyncChangeType change_type, const SyncData& sync_data);
+  SyncChange(
+      const tracked_objects::Location& from_here,
+      SyncChangeType change_type,
+      const SyncData& sync_data);
   ~SyncChange();
 
   // Copy constructor and assignment operator welcome.
@@ -56,6 +60,8 @@ class SyncChange {
   std::string ToString() const;
 
  private:
+  tracked_objects::Location location_;
+
   SyncChangeType change_type_;
 
   // An immutable container for the data of this SyncChange. Whenever
diff --git a/sync/api/sync_change_unittest.cc b/sync/api/sync_change_unittest.cc
index 765bcdf..f5aab08 100644
--- a/sync/api/sync_change_unittest.cc
+++ b/sync/api/sync_change_unittest.cc
@@ -25,7 +25,8 @@ typedef testing::Test SyncChangeTest;
 TEST_F(SyncChangeTest, LocalDelete) {
   SyncChange::SyncChangeType change_type = SyncChange::ACTION_DELETE;
   std::string tag = "client_tag";
-  SyncChange e(change_type,
+  SyncChange e(FROM_HERE,
+               change_type,
                SyncData::CreateLocalDelete(tag, syncer::PREFERENCES));
   EXPECT_EQ(change_type, e.change_type());
   EXPECT_EQ(tag, e.sync_data().GetTag());
@@ -39,7 +40,8 @@ TEST_F(SyncChangeTest, LocalUpdate) {
   pref_specifics->set_name("test");
   std::string tag = "client_tag";
   std::string title = "client_title";
-  SyncChange e(change_type,
+  SyncChange e(FROM_HERE,
+               change_type,
                SyncData::CreateLocalData(tag, title, specifics));
   EXPECT_EQ(change_type, e.change_type());
   EXPECT_EQ(tag, e.sync_data().GetTag());
@@ -58,7 +60,8 @@ TEST_F(SyncChangeTest, LocalAdd) {
   pref_specifics->set_name("test");
   std::string tag = "client_tag";
   std::string title = "client_title";
-  SyncChange e(change_type,
+  SyncChange e(FROM_HERE,
+               change_type,
                SyncData::CreateLocalData(tag, title, specifics));
   EXPECT_EQ(change_type, e.change_type());
   EXPECT_EQ(tag, e.sync_data().GetTag());
@@ -79,6 +82,7 @@ TEST_F(SyncChangeTest, SyncerChanges) {
       update_specifics.mutable_preference();
   pref_specifics->set_name("update");
   change_list.push_back(SyncChange(
+      FROM_HERE,
       SyncChange::ACTION_UPDATE,
       SyncData::CreateRemoteData(1, update_specifics)));
 
@@ -87,6 +91,7 @@ TEST_F(SyncChangeTest, SyncerChanges) {
   pref_specifics = add_specifics.mutable_preference();
   pref_specifics->set_name("add");
   change_list.push_back(SyncChange(
+      FROM_HERE,
       SyncChange::ACTION_ADD,
       SyncData::CreateRemoteData(2, add_specifics)));
 
@@ -95,6 +100,7 @@ TEST_F(SyncChangeTest, SyncerChanges) {
   pref_specifics = delete_specifics.mutable_preference();
   pref_specifics->set_name("add");
   change_list.push_back(SyncChange(
+      FROM_HERE,
       SyncChange::ACTION_DELETE,
       SyncData::CreateRemoteData(3, delete_specifics)));