Make the Datatypes using new syncapi upload unrecoverable errors to breakpad.

BUG=
TEST=

Review URL: http://codereview.chromium.org/10061002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133251 0039d316-1c4b-4281-b951-d872f2087c98

40 files changed, 522 insertions, 175 deletions

diff --git a/chrome/browser/extensions/app_notification_manager.cc b/chrome/browser/extensions/app_notification_manager.cc
index c9aca6b..453e0cc 100644
--- a/chrome/browser/extensions/app_notification_manager.cc
+++ b/chrome/browser/extensions/app_notification_manager.cc
@@ -13,6 +13,7 @@
 #include "base/stl_util.h"
 #include "base/time.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/public/browser/notification_service.h"
@@ -305,9 +306,11 @@ SyncError AppNotificationManager::ProcessSyncChanges(
     const SyncChangeList& change_list) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(loaded());
-  if (!models_associated_)
-    return SyncError(FROM_HERE, "Models not yet associated.",
-                     syncable::APP_NOTIFICATIONS);
+  if (!models_associated_) {
+    return sync_error_factory_->CreateAndUploadError(
+        FROM_HERE,
+        "Models not yet associated.");
+  }
 
   AutoReset<bool> processing_changes(&processing_syncer_changes_, true);
 
@@ -328,10 +331,10 @@ SyncError AppNotificationManager::ProcessSyncChanges(
         new_notif->extension_id(), new_notif->guid());
     if (existing_notif && existing_notif->is_local()) {
       NOTREACHED() << "Matched with notification marked as local";
-      error = SyncError(FROM_HERE,
+      error = sync_error_factory_->CreateAndUploadError(
+          FROM_HERE,
           "ProcessSyncChanges received a local only notification" +
-          SyncChange::ChangeTypeToString(change_type),
-          syncable::APP_NOTIFICATIONS);
+              SyncChange::ChangeTypeToString(change_type));
       continue;
     }
 
@@ -382,7 +385,8 @@ SyncError AppNotificationManager::ProcessSyncChanges(
 SyncError AppNotificationManager::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // AppNotificationDataTypeController ensures that modei is fully should before
   // this method is called by waiting until the load notification is received
@@ -391,7 +395,9 @@ SyncError AppNotificationManager::MergeDataAndStartSyncing(
   DCHECK_EQ(type, syncable::APP_NOTIFICATIONS);
   DCHECK(!sync_processor_.get());
   DCHECK(sync_processor.get());
+  DCHECK(sync_error_factory.get());
   sync_processor_ = sync_processor.Pass();
+  sync_error_factory_ = sync_error_factory.Pass();
 
   // We may add, or remove notifications here, so ensure we don't step on
   // our own toes.
@@ -415,10 +421,10 @@ SyncError AppNotificationManager::MergeDataAndStartSyncing(
       // Local notification should always match with sync notification as
       // notifications are immutable.
       if (local_notif->is_local() || !sync_notif->Equals(*local_notif)) {
-        return SyncError(FROM_HERE,
+        return sync_error_factory_->CreateAndUploadError(
+             FROM_HERE,
             "MergeDataAndStartSyncing failed: local notification and sync "
-            "notification have same guid but different data.",
-            syncable::APP_NOTIFICATIONS);
+            "notification have same guid but different data.");
       }
     } else {
       // Sync model has a notification that local model does not, add it.
@@ -444,6 +450,7 @@ void AppNotificationManager::StopSyncing(syncable::ModelType type) {
   DCHECK_EQ(type, syncable::APP_NOTIFICATIONS);
   models_associated_ = false;
   sync_processor_.reset();
+  sync_error_factory_.reset();
 }
 
 void AppNotificationManager::SyncAddChange(const AppNotification& notif) {
diff --git a/chrome/browser/extensions/app_notification_manager.h b/chrome/browser/extensions/app_notification_manager.h
index fae3b9e..44bdd9b 100644
--- a/chrome/browser/extensions/app_notification_manager.h
+++ b/chrome/browser/extensions/app_notification_manager.h
@@ -24,6 +24,7 @@
 
 class PerfTimer;
 class Profile;
+class SyncErrorFactory;
 
 // This class keeps track of notifications for installed apps.
 class AppNotificationManager
@@ -73,7 +74,8 @@ class AppNotificationManager
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
 
  private:
@@ -156,6 +158,10 @@ class AppNotificationManager
 
   // Sync change processor we use to push all our changes.
   scoped_ptr<SyncChangeProcessor> sync_processor_;
+
+  // Sync error handler that we use to create errors from.
+  scoped_ptr<SyncErrorFactory> sync_error_factory_;
+
   // Whether the sync model is associated with the local model.
   // In other words, whether we are ready to apply sync changes.
   bool models_associated_;
diff --git a/chrome/browser/extensions/app_notification_manager_sync_unittest.cc b/chrome/browser/extensions/app_notification_manager_sync_unittest.cc
index 6a498f4..d311360c 100644
--- a/chrome/browser/extensions/app_notification_manager_sync_unittest.cc
+++ b/chrome/browser/extensions/app_notification_manager_sync_unittest.cc
@@ -8,6 +8,8 @@
 #include "base/string_number_conversions.h"
 #include "chrome/browser/extensions/app_notification.h"
 #include "chrome/browser/extensions/app_notification_manager.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
+#include "chrome/browser/sync/api/sync_error_factory_mock.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/test/test_browser_thread.h"
 #include "sync/protocol/app_notification_specifics.pb.h"
@@ -15,6 +17,8 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::BrowserThread;
+using ::testing::_;
+using ::testing::Return;
 
 namespace {
 
@@ -303,7 +307,8 @@ TEST_F(AppNotificationManagerSyncTest, ModelAssocBothEmpty) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),  // Empty.
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(0U, model()->GetAllSyncData(syncable::APP_NOTIFICATIONS).size());
   EXPECT_EQ(0U, processor()->change_list_size());
@@ -320,7 +325,8 @@ TEST_F(AppNotificationManagerSyncTest, ModelAssocModelEmpty) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       initial_data,
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(4U, model()->GetAllSyncData(syncable::APP_NOTIFICATIONS).size());
   // Model should all of the initial sync data.
@@ -357,7 +363,8 @@ TEST_F(AppNotificationManagerSyncTest, ModelAssocBothNonEmptyNoOverlap) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       initial_data,
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(6U, model()->GetAllSyncData(syncable::APP_NOTIFICATIONS).size());
   for (SyncDataList::const_iterator iter = initial_data.begin();
@@ -408,7 +415,8 @@ TEST_F(AppNotificationManagerSyncTest, ModelAssocBothNonEmptySomeOverlap) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       initial_data,
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(6U, model()->GetAllSyncData(syncable::APP_NOTIFICATIONS).size());
   for (SyncDataList::const_iterator iter = initial_data.begin();
@@ -453,10 +461,16 @@ TEST_F(AppNotificationManagerSyncTest, ModelAssocBothNonEmptyTitleMismatch) {
   initial_data.push_back(
       AppNotificationManager::CreateSyncDataFromNotification(*n1_a));
 
+  scoped_ptr<SyncErrorFactoryMock> error_handler(new SyncErrorFactoryMock());
+  EXPECT_CALL(*error_handler, CreateAndUploadError(_, _)).
+      WillOnce(
+          Return(SyncError(FROM_HERE, "error", syncable::APP_NOTIFICATIONS)));
+
   SyncError sync_error = model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       initial_data,
-      PassProcessor());
+      PassProcessor(),
+      error_handler.PassAs<SyncErrorFactory>());
 
   EXPECT_TRUE(sync_error.IsSet());
   EXPECT_EQ(syncable::APP_NOTIFICATIONS, sync_error.type());
@@ -477,10 +491,16 @@ TEST_F(AppNotificationManagerSyncTest, ModelAssocBothNonEmptyMatchesLocal) {
   initial_data.push_back(
       AppNotificationManager::CreateSyncDataFromNotification(*n2_a));
 
+  scoped_ptr<SyncErrorFactoryMock> error_handler(new SyncErrorFactoryMock());
+  EXPECT_CALL(*error_handler, CreateAndUploadError(_, _)).
+      WillOnce(
+          Return(SyncError(FROM_HERE, "error", syncable::APP_NOTIFICATIONS)));
+
   SyncError sync_error = model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       initial_data,
-      PassProcessor());
+      PassProcessor(),
+      error_handler.PassAs<SyncErrorFactory>());
 
   EXPECT_TRUE(sync_error.IsSet());
   EXPECT_EQ(syncable::APP_NOTIFICATIONS, sync_error.type());
@@ -493,7 +513,8 @@ TEST_F(AppNotificationManagerSyncTest, ProcessSyncChangesEmptyModel) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Set up a bunch of ADDs.
   SyncChangeList changes;
@@ -519,7 +540,8 @@ TEST_F(AppNotificationManagerSyncTest, ProcessSyncChangesNonEmptyModel) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Some adds and some deletes.
   SyncChangeList changes;
@@ -544,7 +566,8 @@ TEST_F(AppNotificationManagerSyncTest, ProcessSyncChangesIgnoreBadAdd) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Some adds and some deletes.
   SyncChangeList changes;
@@ -567,7 +590,8 @@ TEST_F(AppNotificationManagerSyncTest, ProcessSyncChangesIgnoreBadDelete) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Some adds and some deletes.
   SyncChangeList changes;
@@ -590,7 +614,8 @@ TEST_F(AppNotificationManagerSyncTest, ProcessSyncChangesIgnoreBadUpdates) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Some adds and some deletes.
   SyncChangeList changes;
@@ -614,7 +639,8 @@ TEST_F(AppNotificationManagerSyncTest, ProcessSyncChangesEmptyModelWithMax) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   for (unsigned int i = 0;
        i < AppNotificationManager::kMaxNotificationPerApp * 2; i++) {
     SyncChangeList changes;
@@ -636,17 +662,6 @@ TEST_F(AppNotificationManagerSyncTest, ProcessSyncChangesEmptyModelWithMax) {
   }
 }
 
-// Process sync changes should return error if model association is not done.
-TEST_F(AppNotificationManagerSyncTest,
-       ProcessSyncChangesErrorModelAssocNotDone) {
-  SyncChangeList changes;
-
-  SyncError sync_error = model()->ProcessSyncChanges(FROM_HERE, changes);
-  EXPECT_TRUE(sync_error.IsSet());
-  EXPECT_EQ(syncable::APP_NOTIFICATIONS, sync_error.type());
-  EXPECT_EQ(0U, processor()->change_list_size());
-}
-
 // Stop syncing sets state correctly.
 TEST_F(AppNotificationManagerSyncTest, StopSyncing) {
   EXPECT_FALSE(model()->sync_processor_.get());
@@ -655,7 +670,8 @@ TEST_F(AppNotificationManagerSyncTest, StopSyncing) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_TRUE(model()->sync_processor_.get());
   EXPECT_TRUE(model()->models_associated_);
@@ -670,7 +686,8 @@ TEST_F(AppNotificationManagerSyncTest, AddsGetsSynced) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       SyncDataList(),
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   AppNotification* n1 = CreateNotification(1);
   model()->Add(n1);
@@ -707,7 +724,8 @@ TEST_F(AppNotificationManagerSyncTest, ClearAllGetsSynced) {
   model()->MergeDataAndStartSyncing(
       syncable::APP_NOTIFICATIONS,
       initial_data,
-      PassProcessor());
+      PassProcessor(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   model()->ClearAll(ext_id);
 
diff --git a/chrome/browser/extensions/app_sync_bundle.cc b/chrome/browser/extensions/app_sync_bundle.cc
index 43ceb98..29f508b 100644
--- a/chrome/browser/extensions/app_sync_bundle.cc
+++ b/chrome/browser/extensions/app_sync_bundle.cc
@@ -8,6 +8,7 @@
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_sorting.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_set.h"
 
@@ -20,8 +21,10 @@ AppSyncBundle::AppSyncBundle(ExtensionService* extension_service)
 AppSyncBundle::~AppSyncBundle() {}
 
 void AppSyncBundle::SetupSync(SyncChangeProcessor* sync_change_processor,
+                              SyncErrorFactory* sync_error_factory,
                               const SyncDataList& initial_sync_data) {
   sync_processor_.reset(sync_change_processor);
+  sync_error_factory_.reset(sync_error_factory);
 
   for (SyncDataList::const_iterator i = initial_sync_data.begin();
        i != initial_sync_data.end();
@@ -34,6 +37,7 @@ void AppSyncBundle::SetupSync(SyncChangeProcessor* sync_change_processor,
 
 void AppSyncBundle::Reset() {
   sync_processor_.reset();
+  sync_error_factory_.reset();
   synced_apps_.clear();
   pending_sync_data_.clear();
 }
diff --git a/chrome/browser/extensions/app_sync_bundle.h b/chrome/browser/extensions/app_sync_bundle.h
index 9872e9d..5d840c7 100644
--- a/chrome/browser/extensions/app_sync_bundle.h
+++ b/chrome/browser/extensions/app_sync_bundle.h
@@ -20,6 +20,7 @@ class SyncChangeProcessor;
 class Extension;
 class ExtensionService;
 class ExtensionSet;
+class SyncErrorFactory;
 
 namespace extensions {
 
@@ -31,6 +32,7 @@ class AppSyncBundle {
 
   // Setup this bundle to be sync application data.
   void SetupSync(SyncChangeProcessor* sync_proccessor,
+                 SyncErrorFactory* sync_error_factory,
                  const SyncDataList& initial_sync_data);
 
   // Resets this class back to it default values, which will disable all syncing
@@ -89,6 +91,7 @@ class AppSyncBundle {
 
   ExtensionService* extension_service_; // Own us.
   scoped_ptr<SyncChangeProcessor> sync_processor_;
+  scoped_ptr<SyncErrorFactory> sync_error_factory_;
 
   std::set<std::string> synced_apps_;
   std::map<std::string, AppSyncData> pending_sync_data_;
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 0b78711..75e5405 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -75,6 +75,7 @@
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/sync/api/sync_change.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/ui/browser.h"
@@ -1277,17 +1278,22 @@ void ExtensionService::CheckForUpdatesSoon() {
 SyncError ExtensionService::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   CHECK(sync_processor.get());
+  CHECK(sync_error_factory.get());
 
   switch (type) {
     case syncable::EXTENSIONS:
       extension_sync_bundle_.SetupSync(sync_processor.release(),
+                                       sync_error_factory.release(),
                                        initial_sync_data);
       break;
 
     case syncable::APPS:
-      app_sync_bundle_.SetupSync(sync_processor.release(), initial_sync_data);
+      app_sync_bundle_.SetupSync(sync_processor.release(),
+                                 sync_error_factory.release(),
+                                 initial_sync_data);
       break;
 
     default:
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index 7ce5e8b..68e2e5f 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -66,6 +66,7 @@ class GURL;
 class PendingExtensionManager;
 class Profile;
 class SyncData;
+class SyncErrorFactory;
 class Version;
 
 namespace chromeos {
@@ -425,7 +426,8 @@ class ExtensionService
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
   virtual SyncDataList GetAllSyncData(syncable::ModelType type) const OVERRIDE;
   virtual SyncError ProcessSyncChanges(
diff --git a/chrome/browser/extensions/extension_service_unittest.cc b/chrome/browser/extensions/extension_service_unittest.cc
index a4925b2..00a7c70 100644
--- a/chrome/browser/extensions/extension_service_unittest.cc
+++ b/chrome/browser/extensions/extension_service_unittest.cc
@@ -52,6 +52,8 @@
 #include "chrome/browser/prefs/browser_prefs.h"
 #include "chrome/browser/prefs/pref_service_mock_builder.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
+#include "chrome/browser/sync/api/sync_error_factory_mock.h"
 #include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_notification_types.h"
@@ -4005,7 +4007,8 @@ TEST_F(ExtensionServiceTest, GetSyncData) {
   ASSERT_TRUE(extension);
 
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   SyncDataList list = service_->GetAllSyncData(syncable::EXTENSIONS);
   ASSERT_EQ(list.size(), 1U);
@@ -4028,7 +4031,8 @@ TEST_F(ExtensionServiceTest, GetSyncDataTerminated) {
 
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   SyncDataList list = service_->GetAllSyncData(syncable::EXTENSIONS);
   ASSERT_EQ(list.size(), 1U);
@@ -4050,7 +4054,8 @@ TEST_F(ExtensionServiceTest, GetSyncDataFilter) {
 
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::APPS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   SyncDataList list = service_->GetAllSyncData(syncable::EXTENSIONS);
   ASSERT_EQ(list.size(), 0U);
@@ -4064,7 +4069,8 @@ TEST_F(ExtensionServiceTest, GetSyncExtensionDataUserSettings) {
 
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   {
     SyncDataList list = service_->GetAllSyncData(syncable::EXTENSIONS);
@@ -4111,7 +4117,8 @@ TEST_F(ExtensionServiceTest, GetSyncAppDataUserSettings) {
 
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::APPS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   StringOrdinal initial_ordinal = StringOrdinal::CreateInitialOrdinal();
   {
@@ -4159,7 +4166,8 @@ TEST_F(ExtensionServiceTest, GetSyncAppDataUserSettingsOnExtensionMoved) {
 
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::APPS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   service_->OnExtensionMoved(apps[0]->id(), apps[1]->id(), apps[2]->id());
   {
@@ -4197,9 +4205,11 @@ TEST_F(ExtensionServiceTest, GetSyncDataList) {
 
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::APPS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   service_->DisableExtension(page_action, Extension::DISABLE_USER_ACTION);
   TerminateExtension(theme2_crx);
@@ -4212,7 +4222,8 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataUninstall) {
   InitializeEmptyExtensionService();
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   sync_pb::EntitySpecifics specifics;
   sync_pb::ExtensionSpecifics* ext_specifics = specifics.mutable_extension();
@@ -4287,7 +4298,8 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataSettings) {
   InitializeExtensionProcessManager();
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   InstallCRX(data_dir_.AppendASCII("good.crx"), INSTALL_NEW);
   EXPECT_TRUE(service_->IsExtensionEnabled(good_crx));
@@ -4341,7 +4353,8 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataTerminatedExtension) {
   InitializeExtensionServiceWithUpdater();
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   InstallCRX(data_dir_.AppendASCII("good.crx"), INSTALL_NEW);
   TerminateExtension(good_crx);
@@ -4372,7 +4385,8 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataVersionCheck) {
   InitializeRequestContext();
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   InstallCRX(data_dir_.AppendASCII("good.crx"), INSTALL_NEW);
   EXPECT_TRUE(service_->IsExtensionEnabled(good_crx));
@@ -4429,7 +4443,8 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataNotInstalled) {
   InitializeRequestContext();
   TestSyncProcessorStub processor;
   service_->MergeDataAndStartSyncing(syncable::EXTENSIONS, SyncDataList(),
-      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub));
+      scoped_ptr<SyncChangeProcessor>(new TestSyncProcessorStub),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   sync_pb::EntitySpecifics specifics;
   sync_pb::ExtensionSpecifics* ext_specifics = specifics.mutable_extension();
diff --git a/chrome/browser/extensions/extension_sync_bundle.cc b/chrome/browser/extensions/extension_sync_bundle.cc
index d4f5f5b..017915e 100644
--- a/chrome/browser/extensions/extension_sync_bundle.cc
+++ b/chrome/browser/extensions/extension_sync_bundle.cc
@@ -8,6 +8,7 @@
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_sorting.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_set.h"
 
@@ -19,8 +20,10 @@ ExtensionSyncBundle::ExtensionSyncBundle(ExtensionService* extension_service)
 ExtensionSyncBundle::~ExtensionSyncBundle() {}
 
 void ExtensionSyncBundle::SetupSync(SyncChangeProcessor* sync_processor,
+                                    SyncErrorFactory* sync_error_factory,
                                     const SyncDataList& initial_sync_data) {
   sync_processor_.reset(sync_processor);
+  sync_error_factory_.reset(sync_error_factory);
 
   for (SyncDataList::const_iterator i = initial_sync_data.begin();
        i != initial_sync_data.end();
@@ -33,6 +36,7 @@ void ExtensionSyncBundle::SetupSync(SyncChangeProcessor* sync_processor,
 
 void ExtensionSyncBundle::Reset() {
   sync_processor_.reset();
+  sync_error_factory_.reset();
   synced_extensions_.clear();
   pending_sync_data_.clear();
 }
diff --git a/chrome/browser/extensions/extension_sync_bundle.h b/chrome/browser/extensions/extension_sync_bundle.h
index 9c79eb8..1ee248d 100644
--- a/chrome/browser/extensions/extension_sync_bundle.h
+++ b/chrome/browser/extensions/extension_sync_bundle.h
@@ -20,6 +20,7 @@ class SyncChangeProcessor;
 class Extension;
 class ExtensionService;
 class ExtensionSet;
+class SyncErrorFactory;
 
 namespace extensions {
 
@@ -31,6 +32,7 @@ class ExtensionSyncBundle {
 
   // Setup this bundle to be sync extension data.
   void SetupSync(SyncChangeProcessor* sync_processor,
+                 SyncErrorFactory* sync_error_factory,
                  const SyncDataList& initial_sync_data);
 
   // Resets this class back to it default values, which will disable all syncing
@@ -89,6 +91,7 @@ class ExtensionSyncBundle {
 
   ExtensionService* extension_service_;  // Owns us.
   scoped_ptr<SyncChangeProcessor> sync_processor_;
+  scoped_ptr<SyncErrorFactory> sync_error_factory_;
 
   std::set<std::string> synced_extensions_;
   std::map<std::string, ExtensionSyncData> pending_sync_data_;
diff --git a/chrome/browser/extensions/settings/settings_apitest.cc b/chrome/browser/extensions/settings/settings_apitest.cc
index 2bfa7be..1db2c80 100644
--- a/chrome/browser/extensions/settings/settings_apitest.cc
+++ b/chrome/browser/extensions/settings/settings_apitest.cc
@@ -14,6 +14,8 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/api/sync_change.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
+#include "chrome/browser/sync/api/sync_error_factory_mock.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/base/ui_test_utils.h"
@@ -162,7 +164,9 @@ class ExtensionSettingsApiTest : public ExtensionApiTest {
         kModelType,
         SyncDataList(),
         scoped_ptr<SyncChangeProcessor>(
-            new SyncChangeProcessorDelegate(sync_processor))).IsSet());
+            new SyncChangeProcessorDelegate(sync_processor)),
+        scoped_ptr<SyncErrorFactory>(
+            new SyncErrorFactoryMock())).IsSet());
   }
 
   void SendChangesToSyncableService(
diff --git a/chrome/browser/extensions/settings/settings_backend.cc b/chrome/browser/extensions/settings/settings_backend.cc
index c13186d..a20a842 100644
--- a/chrome/browser/extensions/settings/settings_backend.cc
+++ b/chrome/browser/extensions/settings/settings_backend.cc
@@ -16,6 +16,7 @@
 #include "chrome/browser/extensions/settings/settings_storage_quota_enforcer.h"
 #include "chrome/browser/extensions/settings/settings_sync_processor.h"
 #include "chrome/browser/extensions/settings/settings_sync_util.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/public/browser/browser_thread.h"
 
@@ -172,16 +173,19 @@ SyncDataList SettingsBackend::GetAllSyncData(
 SyncError SettingsBackend::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   DCHECK(type == syncable::EXTENSION_SETTINGS ||
          type == syncable::APP_SETTINGS);
   DCHECK_EQ(sync_type_, syncable::UNSPECIFIED);
   DCHECK(!sync_processor_.get());
   DCHECK(sync_processor.get());
+  DCHECK(sync_error_factory.get());
 
   sync_type_ = type;
   sync_processor_ = sync_processor.Pass();
+  sync_error_factory_ = sync_error_factory.Pass();
 
   // Group the initial sync data by extension id.
   std::map<std::string, linked_ptr<DictionaryValue> > grouped_sync_data;
@@ -275,6 +279,7 @@ void SettingsBackend::StopSyncing(syncable::ModelType type) {
 
   sync_type_ = syncable::UNSPECIFIED;
   sync_processor_.reset();
+  sync_error_factory_.reset();
 }
 
 scoped_ptr<SettingsSyncProcessor> SettingsBackend::CreateSettingsSyncProcessor(
diff --git a/chrome/browser/extensions/settings/settings_backend.h b/chrome/browser/extensions/settings/settings_backend.h
index 493d81a..0c5015f 100644
--- a/chrome/browser/extensions/settings/settings_backend.h
+++ b/chrome/browser/extensions/settings/settings_backend.h
@@ -17,6 +17,8 @@
 #include "chrome/browser/extensions/settings/syncable_settings_storage.h"
 #include "chrome/browser/sync/api/syncable_service.h"
 
+class SyncErrorFactory;
+
 namespace extensions {
 
 // Manages SettingsStorage objects for extensions, including routing
@@ -48,7 +50,8 @@ class SettingsBackend : public SyncableService {
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual SyncError ProcessSyncChanges(
       const tracked_objects::Location& from_here,
       const SyncChangeList& change_list) OVERRIDE;
@@ -94,6 +97,9 @@ class SettingsBackend : public SyncableService {
   // Current sync processor, if any.
   scoped_ptr<SyncChangeProcessor> sync_processor_;
 
+  // Current sync error handler if any.
+  scoped_ptr<SyncErrorFactory> sync_error_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(SettingsBackend);
 };
 
diff --git a/chrome/browser/extensions/settings/settings_sync_unittest.cc b/chrome/browser/extensions/settings/settings_sync_unittest.cc
index 175d18f..f19c91dd 100644
--- a/chrome/browser/extensions/settings/settings_sync_unittest.cc
+++ b/chrome/browser/extensions/settings/settings_sync_unittest.cc
@@ -18,6 +18,8 @@
 #include "chrome/browser/extensions/settings/syncable_settings_storage.h"
 #include "chrome/browser/extensions/settings/testing_settings_storage.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
+#include "chrome/browser/sync/api/sync_error_factory_mock.h"
 #include "content/test/test_browser_thread.h"
 
 using content::BrowserThread;
@@ -281,7 +283,8 @@ TEST_F(ExtensionSettingsSyncTest, NoDataDoesNotInvokeSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   AddExtensionAndGetStorage("s2", type);
   EXPECT_EQ(0u, GetAllSyncData(model_type).size());
@@ -322,7 +325,8 @@ TEST_F(ExtensionSettingsSyncTest, InSyncDataDoesNotInvokeSync) {
 
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type, sync_data,
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Already in sync, so no changes.
   EXPECT_EQ(0u, sync_processor_->changes().size());
@@ -358,7 +362,8 @@ TEST_F(ExtensionSettingsSyncTest, LocalDataWithNoSyncDataIsPushedToSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // All settings should have been pushed to sync.
   EXPECT_EQ(2u, sync_processor_->changes().size());
@@ -395,7 +400,8 @@ TEST_F(ExtensionSettingsSyncTest, AnySyncDataOverwritesLocalData) {
       "s2", "bar", value2, model_type));
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type, sync_data,
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   expected1.Set("foo", value1.DeepCopy());
   expected2.Set("bar", value2.DeepCopy());
 
@@ -436,7 +442,8 @@ TEST_F(ExtensionSettingsSyncTest, ProcessSyncChanges) {
 
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type, sync_data,
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   expected2.Set("bar", value2.DeepCopy());
 
   // Make sync add some settings.
@@ -509,7 +516,8 @@ TEST_F(ExtensionSettingsSyncTest, PushToSync) {
 
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type, sync_data,
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Add something locally.
   storage1->Set(DEFAULTS, "bar", value2);
@@ -658,7 +666,8 @@ TEST_F(ExtensionSettingsSyncTest, ExtensionAndAppSettingsSyncSeparately) {
   GetSyncableService(syncable::EXTENSION_SETTINGS)->MergeDataAndStartSyncing(
       syncable::EXTENSION_SETTINGS,
       sync_data,
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   GetSyncableService(syncable::EXTENSION_SETTINGS)->
       StopSyncing(syncable::EXTENSION_SETTINGS);
   EXPECT_EQ(0u, sync_processor_->changes().size());
@@ -672,7 +681,8 @@ TEST_F(ExtensionSettingsSyncTest, ExtensionAndAppSettingsSyncSeparately) {
   GetSyncableService(syncable::APP_SETTINGS)->MergeDataAndStartSyncing(
       syncable::APP_SETTINGS,
       sync_data,
-      app_settings_delegate_.PassAs<SyncChangeProcessor>());
+      app_settings_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   GetSyncableService(syncable::APP_SETTINGS)->
       StopSyncing(syncable::APP_SETTINGS);
   EXPECT_EQ(0u, sync_processor_->changes().size());
@@ -706,7 +716,8 @@ TEST_F(ExtensionSettingsSyncTest, FailingStartSyncingDisablesSync) {
     GetSyncableService(model_type)->MergeDataAndStartSyncing(
         model_type,
         sync_data,
-        sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+        sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+        scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   }
   testing_factory->GetExisting("bad")->SetFailAllRequests(false);
 
@@ -823,7 +834,8 @@ TEST_F(ExtensionSettingsSyncTest, FailingStartSyncingDisablesSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Local settings will have been pushed to sync, since it's empty (in this
   // test; presumably it wouldn't be live, since we've been getting changes).
@@ -900,7 +912,8 @@ TEST_F(ExtensionSettingsSyncTest, FailingProcessChangesDisablesSync) {
     GetSyncableService(model_type)->MergeDataAndStartSyncing(
         model_type,
         sync_data,
-        sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+        sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+        scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   }
 
   EXPECT_EQ(0u, sync_processor_->changes().size());
@@ -1005,7 +1018,8 @@ TEST_F(ExtensionSettingsSyncTest, FailingGetAllSyncDataDoesntStopSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(
       SyncChange::ACTION_ADD,
@@ -1051,7 +1065,8 @@ TEST_F(ExtensionSettingsSyncTest, FailureToReadChangesToPushDisablesSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   testing_factory->GetExisting("bad")->SetFailAllRequests(false);
 
   EXPECT_EQ(
@@ -1102,7 +1117,8 @@ TEST_F(ExtensionSettingsSyncTest, FailureToReadChangesToPushDisablesSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(
       SyncChange::ACTION_ADD,
@@ -1152,7 +1168,8 @@ TEST_F(ExtensionSettingsSyncTest, FailureToPushLocalStateDisablesSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   sync_processor_->SetFailAllRequests(false);
 
   // Changes from good will be send to sync, changes from bad won't.
@@ -1195,7 +1212,8 @@ TEST_F(ExtensionSettingsSyncTest, FailureToPushLocalStateDisablesSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(
       SyncChange::ACTION_ADD,
@@ -1238,7 +1256,8 @@ TEST_F(ExtensionSettingsSyncTest, FailureToPushLocalChangeDisablesSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // bad will fail to send changes.
   good->Set(DEFAULTS, "foo", fooValue);
@@ -1291,7 +1310,8 @@ TEST_F(ExtensionSettingsSyncTest, FailureToPushLocalChangeDisablesSync) {
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   EXPECT_EQ(
       SyncChange::ACTION_ADD,
@@ -1332,7 +1352,8 @@ TEST_F(ExtensionSettingsSyncTest,
   GetSyncableService(model_type)->MergeDataAndStartSyncing(
       model_type,
       SyncDataList(),
-      sync_processor_delegate_.PassAs<SyncChangeProcessor>());
+      sync_processor_delegate_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   // Large local change rejected and doesn't get sent out.
   SettingsStorage* storage1 = AddExtensionAndGetStorage("s1", type);
diff --git a/chrome/browser/extensions/test_extension_service.cc b/chrome/browser/extensions/test_extension_service.cc
index 76d50cd..7ac2abe 100644
--- a/chrome/browser/extensions/test_extension_service.cc
+++ b/chrome/browser/extensions/test_extension_service.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/extensions/crx_installer.h"
 #include "chrome/browser/extensions/extension_sync_data.h"
 #include "chrome/browser/extensions/test_extension_service.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TestExtensionService::~TestExtensionService() {}
@@ -73,7 +74,8 @@ void TestExtensionService::CheckForUpdatesSoon() {
 SyncError TestExtensionService::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   ADD_FAILURE();
   return SyncError();
 }
diff --git a/chrome/browser/extensions/test_extension_service.h b/chrome/browser/extensions/test_extension_service.h
index afbe71e..3a80d67 100644
--- a/chrome/browser/extensions/test_extension_service.h
+++ b/chrome/browser/extensions/test_extension_service.h
@@ -12,6 +12,7 @@
 #include "chrome/browser/extensions/extension_service.h"
 
 class CrxInstaller;
+class SyncErrorFactory;
 
 // Implemention of ExtensionServiceInterface with default
 // implementations for methods that add failures.  You should subclass
@@ -47,7 +48,8 @@ class TestExtensionService : public ExtensionServiceInterface {
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
   virtual SyncDataList GetAllSyncData(syncable::ModelType type) const OVERRIDE;
   virtual SyncError ProcessSyncChanges(
diff --git a/chrome/browser/prefs/pref_model_associator.cc b/chrome/browser/prefs/pref_model_associator.cc
index b70302a..16dc0c3 100644
--- a/chrome/browser/prefs/pref_model_associator.cc
+++ b/chrome/browser/prefs/pref_model_associator.cc
@@ -12,6 +12,7 @@
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/sync/api/sync_change.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "sync/protocol/preference_specifics.pb.h"
@@ -107,13 +108,16 @@ void PrefModelAssociator::InitPrefAndAssociate(
 SyncError PrefModelAssociator::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   DCHECK_EQ(type, PREFERENCES);
   DCHECK(CalledOnValidThread());
   DCHECK(pref_service_);
   DCHECK(!sync_processor_.get());
   DCHECK(sync_processor.get());
+  DCHECK(sync_error_factory.get());
   sync_processor_ = sync_processor.Pass();
+  sync_error_factory_ = sync_error_factory.Pass();
 
   SyncChangeList new_changes;
   std::set<std::string> remaining_preferences = registered_preferences_;
@@ -161,6 +165,7 @@ void PrefModelAssociator::StopSyncing(syncable::ModelType type) {
   DCHECK_EQ(type, PREFERENCES);
   models_associated_ = false;
   sync_processor_.reset();
+  sync_error_factory_.reset();
 }
 
 Value* PrefModelAssociator::MergePreference(
diff --git a/chrome/browser/prefs/pref_model_associator.h b/chrome/browser/prefs/pref_model_associator.h
index de4b645..6d0bb52 100644
--- a/chrome/browser/prefs/pref_model_associator.h
+++ b/chrome/browser/prefs/pref_model_associator.h
@@ -43,7 +43,8 @@ class PrefModelAssociator
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
 
   // Returns the list of preference names that are registered as syncable, and
@@ -143,6 +144,9 @@ class PrefModelAssociator
   // Sync's SyncChange handler. We push all our changes through this.
   scoped_ptr<SyncChangeProcessor> sync_processor_;
 
+  // Sync's error handler. We use this to create sync errors.
+  scoped_ptr<SyncErrorFactory> sync_error_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(PrefModelAssociator);
 };
 
diff --git a/chrome/browser/search_engines/template_url_service.cc b/chrome/browser/search_engines/template_url_service.cc
index fb6f31e..a2f99ae4 100644
--- a/chrome/browser/search_engines/template_url_service.cc
+++ b/chrome/browser/search_engines/template_url_service.cc
@@ -34,6 +34,7 @@
 #include "chrome/browser/search_engines/template_url_service_observer.h"
 #include "chrome/browser/search_engines/util.h"
 #include "chrome/browser/sync/api/sync_change.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/env_vars.h"
@@ -846,9 +847,10 @@ SyncError TemplateURLService::ProcessSyncChanges(
       //  . Trying to DELETE or UPDATE a non-existent search engine.
       //  . Trying to ADD a search engine that already exists.
       NOTREACHED() << "Unexpected sync change state.";
-      error = SyncError(FROM_HERE, "ProcessSyncChanges failed on ChangeType " +
-          SyncChange::ChangeTypeToString(iter->change_type()),
-          syncable::SEARCH_ENGINES);
+      error = sync_error_factory_->CreateAndUploadError(
+            FROM_HERE,
+            "ProcessSyncChanges failed on ChangeType " +
+                SyncChange::ChangeTypeToString(iter->change_type()));
     }
   }
 
@@ -865,12 +867,15 @@ SyncError TemplateURLService::ProcessSyncChanges(
 SyncError TemplateURLService::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   DCHECK(loaded());
   DCHECK_EQ(type, syncable::SEARCH_ENGINES);
   DCHECK(!sync_processor_.get());
   DCHECK(sync_processor.get());
+  DCHECK(sync_error_factory.get());
   sync_processor_ = sync_processor.Pass();
+  sync_error_factory_ = sync_error_factory.Pass();
 
   // We just started syncing, so set our wait-for-default flag if we are
   // expecting a default from Sync.
@@ -972,6 +977,7 @@ void TemplateURLService::StopSyncing(syncable::ModelType type) {
   DCHECK_EQ(type, syncable::SEARCH_ENGINES);
   models_associated_ = false;
   sync_processor_.reset();
+  sync_error_factory_.reset();
 }
 
 void TemplateURLService::ProcessTemplateURLChange(
diff --git a/chrome/browser/search_engines/template_url_service.h b/chrome/browser/search_engines/template_url_service.h
index 067bceb..476797e 100644
--- a/chrome/browser/search_engines/template_url_service.h
+++ b/chrome/browser/search_engines/template_url_service.h
@@ -32,6 +32,7 @@ class Profile;
 class SearchHostToURLsMap;
 class SearchTermsData;
 class SyncData;
+class SyncErrorFactory;
 class TemplateURLServiceObserver;
 
 namespace history {
@@ -280,7 +281,8 @@ class TemplateURLService : public WebDataServiceConsumer,
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
 
   // Processes a local TemplateURL change for Sync. |turl| is the TemplateURL
@@ -598,6 +600,9 @@ class TemplateURLService : public WebDataServiceConsumer,
   // Sync's SyncChange handler. We push all our changes through this.
   scoped_ptr<SyncChangeProcessor> sync_processor_;
 
+  // Sync's error handler. We use it to create a sync error.
+  scoped_ptr<SyncErrorFactory> sync_error_factory_;
+
   // Whether or not we are waiting on the default search provider to come in
   // from Sync. This is to facilitate the fact that changes to the value of
   // prefs::kSyncedDefaultSearchProviderGUID do not always come before the
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 9fb42a4..a7ba778 100644
--- a/chrome/browser/search_engines/template_url_service_sync_unittest.cc
+++ b/chrome/browser/search_engines/template_url_service_sync_unittest.cc
@@ -10,6 +10,8 @@
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/search_engines/template_url_service_test_util.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
+#include "chrome/browser/sync/api/sync_error_factory_mock.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_pref_service.h"
@@ -179,6 +181,7 @@ class TemplateURLServiceSyncTest : public testing::Test {
   TestingProfile* profile_a() { return test_util_a_.profile(); }
   TestChangeProcessor* processor() { return sync_processor_.get(); }
   scoped_ptr<SyncChangeProcessor> PassProcessor();
+  scoped_ptr<SyncErrorFactory> CreateAndPassSyncErrorFactory();
 
   // Create a TemplateURL with some test values. The caller owns the returned
   // TemplateURL*.
@@ -251,6 +254,11 @@ scoped_ptr<SyncChangeProcessor> TemplateURLServiceSyncTest::PassProcessor() {
   return sync_processor_delegate_.PassAs<SyncChangeProcessor>();
 }
 
+scoped_ptr<SyncErrorFactory> TemplateURLServiceSyncTest::
+    CreateAndPassSyncErrorFactory() {
+  return scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock());
+}
+
 TemplateURL* TemplateURLServiceSyncTest::CreateTestTemplateURL(
     const string16& keyword,
     const std::string& url,
@@ -574,8 +582,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeSyncAndLocalURLDuplicates) {
 }
 
 TEST_F(TemplateURLServiceSyncTest, StartSyncEmpty) {
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, SyncDataList(),
-                                    PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, SyncDataList(),
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   EXPECT_EQ(0U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
   EXPECT_EQ(0U, processor()->change_list_size());
@@ -583,8 +593,11 @@ TEST_F(TemplateURLServiceSyncTest, StartSyncEmpty) {
 
 TEST_F(TemplateURLServiceSyncTest, MergeIntoEmpty) {
   SyncDataList initial_data = CreateInitialSyncData();
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, initial_data,
-                                    PassProcessor());
+
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   EXPECT_EQ(3U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
   // We expect the model to have accepted all of the initial sync data. Search
@@ -607,8 +620,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeInAllNewData) {
                                      "http://bing.com", "xyz"));
   SyncDataList initial_data = CreateInitialSyncData();
 
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, initial_data,
-                                    PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   EXPECT_EQ(6U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
   // We expect the model to have accepted all of the initial sync data. Search
@@ -640,8 +655,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeSyncIsTheSame) {
     model()->Add(converted);
   }
 
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, initial_data,
-                                    PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   EXPECT_EQ(3U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
   for (SyncDataList::const_iterator iter = initial_data.begin();
@@ -673,8 +690,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeUpdateFromSync) {
   initial_data.push_back(
       TemplateURLService::CreateSyncDataFromTemplateURL(*turl2_older));
 
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, initial_data,
-                                    PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Both were local updates, so we expect the same count.
   EXPECT_EQ(2U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
@@ -704,8 +723,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeAddFromOlderSyncData) {
   model()->Add(CreateTestTemplateURL(ASCIIToUTF16("unique"),
                                      "http://unique.com", "ccc"));  // add
 
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, CreateInitialSyncData(),
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // The dupe results in a merge. The other two should be added to the model.
   EXPECT_EQ(5U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
@@ -762,8 +783,11 @@ TEST_F(TemplateURLServiceSyncTest, MergeAddFromNewerSyncData) {
   model()->Add(CreateTestTemplateURL(ASCIIToUTF16("unique"),
                                      "http://unique.com", "ccc", 10));  // add
 
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(),
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // The dupe results in a merge. The other two should be added to the model.
   EXPECT_EQ(5U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
@@ -801,8 +825,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeAddFromNewerSyncData) {
 
 TEST_F(TemplateURLServiceSyncTest, ProcessChangesEmptyModel) {
   // We initially have no data.
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, SyncDataList(),
-                                    PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, SyncDataList(),
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Set up a bunch of ADDs.
   SyncChangeList changes;
@@ -823,8 +849,10 @@ TEST_F(TemplateURLServiceSyncTest, ProcessChangesEmptyModel) {
 }
 
 TEST_F(TemplateURLServiceSyncTest, ProcessChangesNoConflicts) {
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Process different types of changes, without conflicts.
   SyncChangeList changes;
@@ -852,8 +880,10 @@ TEST_F(TemplateURLServiceSyncTest, ProcessChangesNoConflicts) {
 }
 
 TEST_F(TemplateURLServiceSyncTest, ProcessChangesWithConflictsSyncWins) {
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Process different types of changes, with conflicts. Note that all this data
   // has a newer timestamp, so Sync will win in these scenarios.
@@ -888,8 +918,10 @@ TEST_F(TemplateURLServiceSyncTest, ProcessChangesWithConflictsSyncWins) {
 }
 
 TEST_F(TemplateURLServiceSyncTest, ProcessChangesWithConflictsLocalWins) {
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Process different types of changes, with conflicts. Note that all this data
   // has an older timestamp, so the local data will win in these scenarios.
@@ -935,8 +967,10 @@ TEST_F(TemplateURLServiceSyncTest, ProcessChangesWithConflictsLocalWins) {
 TEST_F(TemplateURLServiceSyncTest, ProcessTemplateURLChange) {
   // Ensure that ProcessTemplateURLChange is called and pushes the correct
   // changes to Sync whenever local changes are made to TemplateURLs.
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Add a new search engine.
   TemplateURL* new_turl =
@@ -970,8 +1004,10 @@ TEST_F(TemplateURLServiceSyncTest, ProcessTemplateURLChange) {
 
 TEST_F(TemplateURLServiceSyncTest, MergeTwoClientsBasic) {
   // Start off B with some empty data.
-  model_b()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                      CreateInitialSyncData(), PassProcessor());
+  model_b()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Merge A and B. All of B's data should transfer over to A, which initially
   // has no data.
@@ -979,7 +1015,8 @@ TEST_F(TemplateURLServiceSyncTest, MergeTwoClientsBasic) {
       new SyncChangeProcessorDelegate(model_b()));
   model_a()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
       model_b()->GetAllSyncData(syncable::SEARCH_ENGINES),
-      delegate_b.PassAs<SyncChangeProcessor>());
+      delegate_b.PassAs<SyncChangeProcessor>(),
+      CreateAndPassSyncErrorFactory());
 
   // They should be consistent.
   AssertEquals(model_a()->GetAllSyncData(syncable::SEARCH_ENGINES),
@@ -988,8 +1025,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeTwoClientsBasic) {
 
 TEST_F(TemplateURLServiceSyncTest, MergeTwoClientsDupesAndConflicts) {
   // Start off B with some empty data.
-  model_b()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                      CreateInitialSyncData(), PassProcessor());
+  model_b()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Set up A so we have some interesting duplicates and conflicts.
   model_a()->Add(CreateTestTemplateURL(ASCIIToUTF16("key4"), "http://key4.com",
@@ -1004,9 +1043,11 @@ TEST_F(TemplateURLServiceSyncTest, MergeTwoClientsDupesAndConflicts) {
   // Merge A and B.
   scoped_ptr<SyncChangeProcessorDelegate> delegate_b(
       new SyncChangeProcessorDelegate(model_b()));
-  model_a()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
+  model_a()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
       model_b()->GetAllSyncData(syncable::SEARCH_ENGINES),
-      delegate_b.PassAs<SyncChangeProcessor>());
+      delegate_b.PassAs<SyncChangeProcessor>(),
+      CreateAndPassSyncErrorFactory());
 
   // They should be consistent.
   AssertEquals(model_a()->GetAllSyncData(syncable::SEARCH_ENGINES),
@@ -1014,8 +1055,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeTwoClientsDupesAndConflicts) {
 }
 
 TEST_F(TemplateURLServiceSyncTest, StopSyncing) {
-  SyncError error = model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-      CreateInitialSyncData(), PassProcessor());
+  SyncError error = model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
   ASSERT_FALSE(error.IsSet());
   model()->StopSyncing(syncable::SEARCH_ENGINES);
 
@@ -1033,8 +1076,10 @@ TEST_F(TemplateURLServiceSyncTest, StopSyncing) {
 
 TEST_F(TemplateURLServiceSyncTest, SyncErrorOnInitialSync) {
   processor()->set_erroneous(true);
-  SyncError error = model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-      CreateInitialSyncData(), PassProcessor());
+  SyncError error = model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
   EXPECT_TRUE(error.IsSet());
 
   // Ensure that if the initial merge was erroneous, then subsequence attempts
@@ -1056,8 +1101,10 @@ TEST_F(TemplateURLServiceSyncTest, SyncErrorOnInitialSync) {
 TEST_F(TemplateURLServiceSyncTest, SyncErrorOnLaterSync) {
   // Ensure that if the SyncProcessor succeeds in the initial merge, but fails
   // in future ProcessSyncChanges, we still return an error.
-  SyncError error = model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-      CreateInitialSyncData(), PassProcessor());
+  SyncError error = model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      CreateInitialSyncData(), PassProcessor(),
+      CreateAndPassSyncErrorFactory());
   ASSERT_FALSE(error.IsSet());
 
   SyncChangeList changes;
@@ -1078,8 +1125,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeTwiceWithSameSyncData) {
   model()->Add(CreateTestTemplateURL(ASCIIToUTF16("key1"), "http://key1.com",
                                      "key1", 10));  // earlier
 
-  SyncError error = model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-      initial_data, PassProcessor());
+  SyncError error = model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      initial_data, PassProcessor(),
+      CreateAndPassSyncErrorFactory());
   ASSERT_FALSE(error.IsSet());
 
   // We should have updated the original TemplateURL with Sync's version.
@@ -1104,8 +1153,10 @@ TEST_F(TemplateURLServiceSyncTest, MergeTwiceWithSameSyncData) {
   model()->StopSyncing(syncable::SEARCH_ENGINES);
   sync_processor_delegate_.reset(new SyncChangeProcessorDelegate(
       sync_processor_.get()));
-  error = model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                            initial_data, PassProcessor());
+  error = model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      initial_data, PassProcessor(),
+      CreateAndPassSyncErrorFactory());
   ASSERT_FALSE(error.IsSet());
 
   // Check that the TemplateURL was not modified.
@@ -1120,8 +1171,10 @@ TEST_F(TemplateURLServiceSyncTest, SyncedDefaultGUIDArrivesFirst) {
   scoped_ptr<TemplateURL> turl(CreateTestTemplateURL(ASCIIToUTF16("key2"),
       "http://key2.com/{searchTerms}", "key2", 90));
   initial_data[1] = TemplateURLService::CreateSyncDataFromTemplateURL(*turl);
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, initial_data,
-                                    PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
   model()->SetDefaultSearchProvider(model()->GetTemplateURLForGUID("key2"));
 
   EXPECT_EQ(3U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
@@ -1186,8 +1239,11 @@ TEST_F(TemplateURLServiceSyncTest, SyncedDefaultArrivesAfterStartup) {
   scoped_ptr<TemplateURL> turl(CreateTestTemplateURL(ASCIIToUTF16("key2"),
       "http://key2.com/{searchTerms}", "key2", 90));
   initial_data[1] = TemplateURLService::CreateSyncDataFromTemplateURL(*turl);
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, initial_data,
-                                    PassProcessor());
+
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Ensure that the new default has been set.
   EXPECT_EQ(4U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
@@ -1214,8 +1270,11 @@ TEST_F(TemplateURLServiceSyncTest, SyncedDefaultAlreadySetOnStartup) {
   EXPECT_EQ(default_search, model()->GetDefaultSearchProvider());
 
   // Now sync the initial data.
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  SyncDataList initial_data = CreateInitialSyncData();
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   // Ensure that the new entries were added and the default has not changed.
   EXPECT_EQ(4U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
@@ -1225,8 +1284,11 @@ TEST_F(TemplateURLServiceSyncTest, SyncedDefaultAlreadySetOnStartup) {
 TEST_F(TemplateURLServiceSyncTest, SyncWithManagedDefaultSearch) {
   // First start off with a few entries and make sure we can set an unmanaged
   // default search provider.
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    CreateInitialSyncData(), PassProcessor());
+  SyncDataList initial_data = CreateInitialSyncData();
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES, initial_data,
+      PassProcessor(),
+      CreateAndPassSyncErrorFactory());
   model()->SetDefaultSearchProvider(model()->GetTemplateURLForGUID("key2"));
 
   EXPECT_EQ(3U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
@@ -1287,8 +1349,10 @@ TEST_F(TemplateURLServiceSyncTest, SyncMergeDeletesDefault) {
       "http://key1.com/{searchTerms}", "key1", 90));
   initial_data[0] = TemplateURLService::CreateSyncDataFromTemplateURL(*turl);
 
-  model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES,
-                                    initial_data, PassProcessor());
+  model()->MergeDataAndStartSyncing(
+      syncable::SEARCH_ENGINES,
+      initial_data, PassProcessor(),
+      CreateAndPassSyncErrorFactory());
 
   EXPECT_EQ(3U, model()->GetAllSyncData(syncable::SEARCH_ENGINES).size());
   EXPECT_FALSE(model()->GetTemplateURLForGUID("whateverguid"));
@@ -1309,7 +1373,8 @@ TEST_F(TemplateURLServiceSyncTest, DeleteBogusData) {
 
   // Now try to sync the data locally.
   model()->MergeDataAndStartSyncing(syncable::SEARCH_ENGINES, initial_data,
-                                    PassProcessor());
+                                    PassProcessor(),
+                                    CreateAndPassSyncErrorFactory());
 
   // Nothing should have been added, and both bogus entries should be marked for
   // deletion.
diff --git a/chrome/browser/sync/api/fake_syncable_service.cc b/chrome/browser/sync/api/fake_syncable_service.cc
index 2f7d948..7082577 100644
--- a/chrome/browser/sync/api/fake_syncable_service.cc
+++ b/chrome/browser/sync/api/fake_syncable_service.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "chrome/browser/sync/api/fake_syncable_service.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 
 #include "base/location.h"
 
@@ -30,7 +31,8 @@ bool FakeSyncableService::syncing() const {
 SyncError FakeSyncableService::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   sync_processor_ = sync_processor.Pass();
   type_ = type;
   if (!merge_data_and_start_syncing_error_.IsSet()) {
diff --git a/chrome/browser/sync/api/fake_syncable_service.h b/chrome/browser/sync/api/fake_syncable_service.h
index 724985c..3080a630 100644
--- a/chrome/browser/sync/api/fake_syncable_service.h
+++ b/chrome/browser/sync/api/fake_syncable_service.h
@@ -8,6 +8,8 @@
 
 #include "chrome/browser/sync/api/syncable_service.h"
 
+class SyncErrorFactory;
+
 // A fake SyncableService that can return arbitrary values and maintains the
 // syncing status.
 class FakeSyncableService : public SyncableService {
@@ -27,7 +29,8 @@ class FakeSyncableService : public SyncableService {
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
   virtual SyncDataList GetAllSyncData(syncable::ModelType type) const OVERRIDE;
   virtual SyncError ProcessSyncChanges(
diff --git a/chrome/browser/sync/api/sync_error_factory.cc b/chrome/browser/sync/api/sync_error_factory.cc
new file mode 100644
index 0000000..efc3627
--- /dev/null
+++ b/chrome/browser/sync/api/sync_error_factory.cc
@@ -0,0 +1,11 @@
+// Copyright (c) 2012 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.
+
+#include "chrome/browser/sync/api/sync_error_factory.h"
+
+SyncErrorFactory::SyncErrorFactory() {
+}
+
+SyncErrorFactory::~SyncErrorFactory() {
+}
diff --git a/chrome/browser/sync/api/sync_error_factory.h b/chrome/browser/sync/api/sync_error_factory.h
new file mode 100644
index 0000000..05ea918
--- /dev/null
+++ b/chrome/browser/sync/api/sync_error_factory.h
@@ -0,0 +1,26 @@
+// Copyright (c) 2012 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_SYNC_API_SYNC_ERROR_FACTORY_H_
+#define CHROME_BROWSER_SYNC_API_SYNC_ERROR_FACTORY_H_
+#pragma once
+
+#include <string>
+
+#include "base/location.h"
+#include "chrome/browser/sync/api/sync_error.h"
+
+class SyncErrorFactory {
+ public:
+  SyncErrorFactory();
+  virtual ~SyncErrorFactory();
+
+  // Creates a SyncError object and uploads this call stack to breakpad.
+  virtual SyncError CreateAndUploadError(
+      const tracked_objects::Location& location,
+      const std::string& message) = 0;
+};
+
+#endif  // CHROME_BROWSER_SYNC_API_SYNC_ERROR_FACTORY_H_
+
diff --git a/chrome/browser/sync/api/sync_error_factory_mock.cc b/chrome/browser/sync/api/sync_error_factory_mock.cc
new file mode 100644
index 0000000..edb1092
--- /dev/null
+++ b/chrome/browser/sync/api/sync_error_factory_mock.cc
@@ -0,0 +1,12 @@
+// Copyright (c) 2012 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.
+
+#include "chrome/browser/sync/api/sync_error_factory_mock.h"
+
+SyncErrorFactoryMock::SyncErrorFactoryMock() {
+}
+
+SyncErrorFactoryMock::~SyncErrorFactoryMock() {
+}
+
diff --git a/chrome/browser/sync/api/sync_error_factory_mock.h b/chrome/browser/sync/api/sync_error_factory_mock.h
new file mode 100644
index 0000000..555b7b9
--- /dev/null
+++ b/chrome/browser/sync/api/sync_error_factory_mock.h
@@ -0,0 +1,23 @@
+// Copyright (c) 2012 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_SYNC_API_SYNC_ERROR_FACTORY_MOCK_H_
+#define CHROME_BROWSER_SYNC_API_SYNC_ERROR_FACTORY_MOCK_H_
+#pragma once
+
+#include "chrome/browser/sync/api/sync_error_factory.h"
+
+#include "testing/gmock/include/gmock/gmock.h"
+
+class SyncErrorFactoryMock : public SyncErrorFactory {
+ public:
+  SyncErrorFactoryMock();
+  virtual ~SyncErrorFactoryMock();
+
+  MOCK_METHOD2(CreateAndUploadError, SyncError(
+      const tracked_objects::Location& location,
+      const std::string& message));
+};
+
+#endif  // CHROME_BROWSER_SYNC_API_SYNC_ERROR_FACTORY_MOCK_H_
diff --git a/chrome/browser/sync/api/syncable_service.h b/chrome/browser/sync/api/syncable_service.h
index 1e1e6a2..800bdc3 100644
--- a/chrome/browser/sync/api/syncable_service.h
+++ b/chrome/browser/sync/api/syncable_service.h
@@ -16,6 +16,8 @@
 #include "chrome/browser/sync/api/sync_error.h"
 #include "sync/syncable/model_type.h"
 
+class SyncErrorFactory;
+
 typedef std::vector<SyncData> SyncDataList;
 
 // TODO(zea): remove SupportsWeakPtr in favor of having all SyncableService
@@ -36,7 +38,8 @@ class SyncableService : public SyncChangeProcessor,
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) = 0;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> error_handler) = 0;
 
   // Stop syncing the specified type and reset state.
   virtual void StopSyncing(syncable::ModelType type) = 0;
diff --git a/chrome/browser/sync/glue/data_type_controller.h b/chrome/browser/sync/glue/data_type_controller.h
index 5ae667d..81f7c68 100644
--- a/chrome/browser/sync/glue/data_type_controller.h
+++ b/chrome/browser/sync/glue/data_type_controller.h
@@ -98,6 +98,7 @@ class DataTypeController
   virtual State state() const = 0;
 
   // Partial implementation of DataTypeErrorHandler.
+  // This is thread safe.
   virtual SyncError CreateAndUploadError(
       const tracked_objects::Location& location,
       const std::string& message,
diff --git a/chrome/browser/sync/glue/new_non_frontend_data_type_controller.cc b/chrome/browser/sync/glue/new_non_frontend_data_type_controller.cc
index 3b7ec84..4741682 100644
--- a/chrome/browser/sync/glue/new_non_frontend_data_type_controller.cc
+++ b/chrome/browser/sync/glue/new_non_frontend_data_type_controller.cc
@@ -129,6 +129,8 @@ void NewNonFrontendDataTypeController::
       type(),
       initial_sync_data,
       scoped_ptr<SyncChangeProcessor>(
+          new SharedChangeProcessorRef(shared_change_processor)),
+      scoped_ptr<SyncErrorFactory>(
           new SharedChangeProcessorRef(shared_change_processor)));
   RecordAssociationTime(base::TimeTicks::Now() - start_time);
   if (error.IsSet()) {
diff --git a/chrome/browser/sync/glue/shared_change_processor.cc b/chrome/browser/sync/glue/shared_change_processor.cc
index e803586..2eed84a7 100644
--- a/chrome/browser/sync/glue/shared_change_processor.cc
+++ b/chrome/browser/sync/glue/shared_change_processor.cc
@@ -19,7 +19,8 @@ SharedChangeProcessor::SharedChangeProcessor()
     : disconnected_(false),
       type_(syncable::UNSPECIFIED),
       sync_service_(NULL),
-      generic_change_processor_(NULL) {
+      generic_change_processor_(NULL),
+      error_handler_(NULL) {
   // We're always created on the UI thread.
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
@@ -59,6 +60,7 @@ base::WeakPtr<SyncableService> SharedChangeProcessor::Connect(
     return base::WeakPtr<SyncableService>();
   type_ = type;
   sync_service_ = sync_service;
+  error_handler_ = error_handler;
   base::WeakPtr<SyncableService> local_service =
       sync_factory->GetSyncableServiceForType(type);
   if (!local_service.get()) {
@@ -79,6 +81,7 @@ bool SharedChangeProcessor::Disconnect() {
   AutoLock lock(monitor_lock_);
   bool was_connected = !disconnected_;
   disconnected_ = true;
+  error_handler_ = NULL;
   return was_connected;
 }
 
@@ -147,4 +150,15 @@ void SharedChangeProcessor::ActivateDataType(
                                   generic_change_processor_);
 }
 
+SyncError SharedChangeProcessor::CreateAndUploadError(
+    const tracked_objects::Location& location,
+    const std::string& message) {
+  AutoLock lock(monitor_lock_);
+  if (!disconnected_) {
+    return error_handler_->CreateAndUploadError(location, message, type_);
+  } else {
+    return SyncError(location, message, type_);
+  }
+}
+
 }  // namespace browser_sync
diff --git a/chrome/browser/sync/glue/shared_change_processor.h b/chrome/browser/sync/glue/shared_change_processor.h
index b87e1f9..17e24a1 100644
--- a/chrome/browser/sync/glue/shared_change_processor.h
+++ b/chrome/browser/sync/glue/shared_change_processor.h
@@ -13,6 +13,7 @@
 #include "base/synchronization/lock.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
 #include "chrome/browser/sync/api/sync_error.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/browser/sync/glue/data_type_error_handler.h"
 #include "sync/engine/model_safe_worker.h"
 
@@ -86,6 +87,10 @@ class SharedChangeProcessor
   // Does nothing if |disconnected_| is true.
   virtual void ActivateDataType(browser_sync::ModelSafeGroup model_safe_group);
 
+  virtual SyncError CreateAndUploadError(
+      const tracked_objects::Location& location,
+      const std::string& message);
+
  protected:
   friend class base::RefCountedThreadSafe<SharedChangeProcessor>;
   virtual ~SharedChangeProcessor();
@@ -112,6 +117,8 @@ class SharedChangeProcessor
   // Used only on |backend_loop_|.
   GenericChangeProcessor* generic_change_processor_;
 
+  DataTypeErrorHandler* error_handler_;
+
   DISALLOW_COPY_AND_ASSIGN(SharedChangeProcessor);
 };
 
diff --git a/chrome/browser/sync/glue/shared_change_processor_ref.cc b/chrome/browser/sync/glue/shared_change_processor_ref.cc
index e0b2a52..153eee0 100644
--- a/chrome/browser/sync/glue/shared_change_processor_ref.cc
+++ b/chrome/browser/sync/glue/shared_change_processor_ref.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -20,4 +20,10 @@ SyncError SharedChangeProcessorRef::ProcessSyncChanges(
   return change_processor_->ProcessSyncChanges(from_here, change_list);
 }
 
+SyncError SharedChangeProcessorRef::CreateAndUploadError(
+    const tracked_objects::Location& from_here,
+    const std::string& message) {
+  return change_processor_->CreateAndUploadError(from_here, message);
+}
+
 }  // namespace browser_sync
diff --git a/chrome/browser/sync/glue/shared_change_processor_ref.h b/chrome/browser/sync/glue/shared_change_processor_ref.h
index 4c73bac..6b79769 100644
--- a/chrome/browser/sync/glue/shared_change_processor_ref.h
+++ b/chrome/browser/sync/glue/shared_change_processor_ref.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -9,13 +9,15 @@
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/browser/sync/glue/shared_change_processor.h"
 
 namespace browser_sync {
 
 // A SyncChangeProcessor stub for interacting with a refcounted
 // SharedChangeProcessor.
-class SharedChangeProcessorRef : public SyncChangeProcessor {
+class SharedChangeProcessorRef : public SyncChangeProcessor,
+                                 public SyncErrorFactory {
  public:
   SharedChangeProcessorRef(
       const scoped_refptr<browser_sync::SharedChangeProcessor>&
@@ -27,6 +29,11 @@ class SharedChangeProcessorRef : public SyncChangeProcessor {
       const tracked_objects::Location& from_here,
       const SyncChangeList& change_list) OVERRIDE;
 
+  // SyncErrorFactory implementation.
+  virtual SyncError CreateAndUploadError(
+      const tracked_objects::Location& from_here,
+      const std::string& message) OVERRIDE;
+
   // Default copy and assign welcome (and safe due to refcounted-ness).
 
  private:
diff --git a/chrome/browser/sync/glue/ui_data_type_controller.cc b/chrome/browser/sync/glue/ui_data_type_controller.cc
index 01aa1f7..9066034 100644
--- a/chrome/browser/sync/glue/ui_data_type_controller.cc
+++ b/chrome/browser/sync/glue/ui_data_type_controller.cc
@@ -131,6 +131,8 @@ void UIDataTypeController::Associate() {
       type(),
       initial_sync_data,
       scoped_ptr<SyncChangeProcessor>(
+          new SharedChangeProcessorRef(shared_change_processor_)),
+      scoped_ptr<SyncErrorFactory>(
           new SharedChangeProcessorRef(shared_change_processor_)));
   RecordAssociationTime(base::TimeTicks::Now() - start_time);
   if (error.IsSet()) {
diff --git a/chrome/browser/webdata/autocomplete_syncable_service.cc b/chrome/browser/webdata/autocomplete_syncable_service.cc
index 7c5678c..fc9fe10 100644
--- a/chrome/browser/webdata/autocomplete_syncable_service.cc
+++ b/chrome/browser/webdata/autocomplete_syncable_service.cc
@@ -10,6 +10,7 @@
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/api/sync_error.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/browser/webdata/autofill_table.h"
 #include "chrome/browser/webdata/web_data_service.h"
 #include "chrome/browser/webdata/web_database.h"
@@ -110,17 +111,20 @@ AutocompleteSyncableService::AutocompleteSyncableService()
 SyncError AutocompleteSyncableService::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> error_handler) {
   DCHECK(CalledOnValidThread());
   DCHECK(!sync_processor_.get());
   DCHECK(sync_processor.get());
+  DCHECK(error_handler.get());
   VLOG(1) << "Associating Autocomplete: MergeDataAndStartSyncing";
 
+  error_handler_ = error_handler.Pass();
   std::vector<AutofillEntry> entries;
   if (!LoadAutofillData(&entries)) {
-    return SyncError(
-        FROM_HERE, "Could not get the autocomplete data from WebDatabase.",
-        model_type());
+    return error_handler_->CreateAndUploadError(
+        FROM_HERE,
+        "Could not get the autocomplete data from WebDatabase.");
   }
 
   AutocompleteEntryMap new_db_entries;
@@ -145,8 +149,11 @@ SyncError AutocompleteSyncableService::MergeDataAndStartSyncing(
   // Check if newly received items need culling.
   bool need_to_cull_data = !synced_expired_entries.empty();
 
-  if (!SaveChangesToWebData(new_synced_entries))
-    return SyncError(FROM_HERE, "Failed to update webdata.", model_type());
+  if (!SaveChangesToWebData(new_synced_entries)) {
+    return error_handler_->CreateAndUploadError(
+        FROM_HERE,
+        "Failed to update webdata.");
+  }
 
   WebDataService::NotifyOfMultipleAutofillChanges(web_data_service_);
   keys_to_ignore_.clear();
@@ -198,6 +205,7 @@ void AutocompleteSyncableService::StopSyncing(syncable::ModelType type) {
   DCHECK_EQ(syncable::AUTOFILL, type);
 
   sync_processor_.reset(NULL);
+  error_handler_.reset();
 }
 
 SyncDataList AutocompleteSyncableService::GetAllSyncData(
@@ -248,10 +256,9 @@ SyncError AutocompleteSyncableService::ProcessSyncChanges(
       case SyncChange::ACTION_UPDATE:
         if (!db_entries.get()) {
           if (!LoadAutofillData(&entries)) {
-            return SyncError(
+            return error_handler_->CreateAndUploadError(
                 FROM_HERE,
-                "Could not get the autocomplete data from WebDatabase.",
-                model_type());
+                "Could not get the autocomplete data from WebDatabase.");
           }
           db_entries.reset(new AutocompleteEntryMap);
           for (std::vector<AutofillEntry>::iterator it = entries.begin();
@@ -277,14 +284,18 @@ SyncError AutocompleteSyncableService::ProcessSyncChanges(
       } break;
       default:
         NOTREACHED() << "Unexpected sync change state.";
-        return SyncError(FROM_HERE, "ProcessSyncChanges failed on ChangeType " +
-                         SyncChange::ChangeTypeToString(i->change_type()),
-                         syncable::AUTOFILL);
+        return error_handler_->CreateAndUploadError(
+            FROM_HERE,
+            "ProcessSyncChanges failed on ChangeType " +
+                 SyncChange::ChangeTypeToString(i->change_type()));
     }
   }
 
-  if (!SaveChangesToWebData(new_entries))
-    return SyncError(FROM_HERE, "Failed to update webdata.", model_type());
+  if (!SaveChangesToWebData(new_entries)) {
+    return error_handler_->CreateAndUploadError(
+        FROM_HERE,
+        "Failed to update webdata.");
+  }
 
   // Remove already expired data.
   for (size_t i = 0; i < ignored_entries.size(); ++i) {
@@ -416,9 +427,9 @@ SyncError AutocompleteSyncableService::AutofillEntryDelete(
     const sync_pb::AutofillSpecifics& autofill) {
   if (!web_data_service_->GetDatabase()->GetAutofillTable()->RemoveFormElement(
           UTF8ToUTF16(autofill.name()), UTF8ToUTF16(autofill.value()))) {
-    return SyncError(FROM_HERE,
-                     "Could not remove autocomplete entry from WebDatabase.",
-                     model_type());
+    return error_handler_->CreateAndUploadError(
+        FROM_HERE,
+        "Could not remove autocomplete entry from WebDatabase.");
   }
   return SyncError();
 }
diff --git a/chrome/browser/webdata/autocomplete_syncable_service.h b/chrome/browser/webdata/autocomplete_syncable_service.h
index f13873d..84d35fa 100644
--- a/chrome/browser/webdata/autocomplete_syncable_service.h
+++ b/chrome/browser/webdata/autocomplete_syncable_service.h
@@ -25,6 +25,7 @@
 #include "content/public/browser/notification_registrar.h"
 
 class ProfileSyncServiceAutofillTest;
+class SyncErrorFactory;
 
 namespace sync_pb {
 class AutofillSpecifics;
@@ -51,7 +52,8 @@ class AutocompleteSyncableService
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> error_handler) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
   virtual SyncDataList GetAllSyncData(syncable::ModelType type) const OVERRIDE;
   virtual SyncError ProcessSyncChanges(
@@ -137,6 +139,10 @@ class AutocompleteSyncableService
   // destroy it in StopSyncing().
   scoped_ptr<SyncChangeProcessor> sync_processor_;
 
+  // We receive ownership of |error_handler_| in MergeDataAndStartSyncing() and
+  // destroy it in StopSyncing().
+  scoped_ptr<SyncErrorFactory> error_handler_;
+
   DISALLOW_COPY_AND_ASSIGN(AutocompleteSyncableService);
 };
 
diff --git a/chrome/browser/webdata/autofill_profile_syncable_service.cc b/chrome/browser/webdata/autofill_profile_syncable_service.cc
index fe1222d..f65327a 100644
--- a/chrome/browser/webdata/autofill_profile_syncable_service.cc
+++ b/chrome/browser/webdata/autofill_profile_syncable_service.cc
@@ -11,6 +11,7 @@
 #include "chrome/browser/autofill/form_group.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/api/sync_error.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
 #include "chrome/browser/webdata/autofill_table.h"
 #include "chrome/browser/webdata/web_data_service.h"
 #include "chrome/browser/webdata/web_database.h"
@@ -59,16 +60,18 @@ AutofillProfileSyncableService::AutofillProfileSyncableService()
 SyncError AutofillProfileSyncableService::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
-    scoped_ptr<SyncChangeProcessor> sync_processor) {
+    scoped_ptr<SyncChangeProcessor> sync_processor,
+    scoped_ptr<SyncErrorFactory> sync_error_factory) {
   DCHECK(CalledOnValidThread());
   DCHECK(!sync_processor_.get());
   DCHECK(sync_processor.get());
+  DCHECK(sync_error_factory.get());
   DVLOG(1) << "Associating Autofill: MergeDataAndStartSyncing";
 
+  sync_error_factory_ = sync_error_factory.Pass();
   if (!LoadAutofillData(&profiles_.get())) {
-    return SyncError(
-        FROM_HERE, "Could not get the autofill data from WebDatabase.",
-        model_type());
+    return sync_error_factory_->CreateAndUploadError(
+        FROM_HERE, "Could not get the autofill data from WebDatabase.");
   }
 
   if (DLOG_IS_ON(INFO)) {
@@ -126,8 +129,11 @@ SyncError AutofillProfileSyncableService::MergeDataAndStartSyncing(
     }
   }
 
-  if (!SaveChangesToWebData(bundle))
-    return SyncError(FROM_HERE, "Failed to update webdata.", model_type());
+  if (!SaveChangesToWebData(bundle)) {
+    return sync_error_factory_->CreateAndUploadError(
+        FROM_HERE,
+        "Failed to update webdata.");
+  }
 
   SyncChangeList new_changes;
   for (GUIDToProfileMap::iterator i = remaining_profiles.begin();
@@ -157,6 +163,7 @@ void AutofillProfileSyncableService::StopSyncing(syncable::ModelType type) {
   DCHECK_EQ(type, syncable::AUTOFILL_PROFILE);
 
   sync_processor_.reset();
+  sync_error_factory_.reset();
   profiles_.reset();
   profiles_map_.clear();
 }
@@ -204,14 +211,18 @@ SyncError AutofillProfileSyncableService::ProcessSyncChanges(
       } break;
       default:
         NOTREACHED() << "Unexpected sync change state.";
-        return SyncError(FROM_HERE, "ProcessSyncChanges failed on ChangeType " +
-                         SyncChange::ChangeTypeToString(i->change_type()),
-                         syncable::AUTOFILL_PROFILE);
+        return sync_error_factory_->CreateAndUploadError(
+              FROM_HERE,
+              "ProcessSyncChanges failed on ChangeType " +
+                  SyncChange::ChangeTypeToString(i->change_type()));
     }
   }
 
-  if (!SaveChangesToWebData(bundle))
-    return SyncError(FROM_HERE, "Failed to update webdata.", model_type());
+  if (!SaveChangesToWebData(bundle)) {
+    return sync_error_factory_->CreateAndUploadError(
+        FROM_HERE,
+        "Failed to update webdata.");
+  }
 
   WebDataService::NotifyOfMultipleAutofillChanges(web_data_service_);
 
diff --git a/chrome/browser/webdata/autofill_profile_syncable_service.h b/chrome/browser/webdata/autofill_profile_syncable_service.h
index 59c1e4a..db3aa5c 100644
--- a/chrome/browser/webdata/autofill_profile_syncable_service.h
+++ b/chrome/browser/webdata/autofill_profile_syncable_service.h
@@ -51,7 +51,8 @@ class AutofillProfileSyncableService
   virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
-      scoped_ptr<SyncChangeProcessor> sync_processor) OVERRIDE;
+      scoped_ptr<SyncChangeProcessor> sync_processor,
+      scoped_ptr<SyncErrorFactory> sync_error_factory) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
   virtual SyncDataList GetAllSyncData(syncable::ModelType type) const OVERRIDE;
   virtual SyncError ProcessSyncChanges(
@@ -164,6 +165,8 @@ class AutofillProfileSyncableService
 
   scoped_ptr<SyncChangeProcessor> sync_processor_;
 
+  scoped_ptr<SyncErrorFactory> sync_error_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(AutofillProfileSyncableService);
 };
 
diff --git a/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc b/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc
index 11a4dc3..5c88795 100644
--- a/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc
+++ b/chrome/browser/webdata/autofill_profile_syncable_service_unittest.cc
@@ -6,6 +6,8 @@
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autofill/autofill_profile.h"
+#include "chrome/browser/sync/api/sync_error_factory.h"
+#include "chrome/browser/sync/api/sync_error_factory_mock.h"
 #include "chrome/browser/sync/internal_api/read_node_mock.h"
 #include "chrome/browser/webdata/autofill_change.h"
 #include "chrome/browser/webdata/autofill_profile_syncable_service.h"
@@ -170,7 +172,8 @@ TEST_F(AutofillProfileSyncableServiceTest, MergeDataAndStartSyncing) {
   // Takes ownership of sync_processor_.
   autofill_syncable_service_.MergeDataAndStartSyncing(
       syncable::AUTOFILL_PROFILE, data_list,
-      sync_processor_.PassAs<SyncChangeProcessor>());
+      sync_processor_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
   autofill_syncable_service_.StopSyncing(syncable::AUTOFILL_PROFILE);
 }
 
@@ -201,7 +204,8 @@ TEST_F(AutofillProfileSyncableServiceTest, GetAllSyncData) {
   // Takes ownership of sync_processor_.
   autofill_syncable_service_.MergeDataAndStartSyncing(
       syncable::AUTOFILL_PROFILE, data_list,
-      sync_processor_.PassAs<SyncChangeProcessor>());
+      sync_processor_.PassAs<SyncChangeProcessor>(),
+      scoped_ptr<SyncErrorFactory>(new SyncErrorFactoryMock()));
 
   SyncDataList data =
       autofill_syncable_service_.GetAllSyncData(syncable::AUTOFILL_PROFILE);