sync: avoid creating a HistoryModelWorker unless it is needed.

We typically add all known workers when Initializing the SyncBackendHost,
but this one is causing crashes and isn't used by default.

BUG=53916,69561
TEST=none

Review URL: http://codereview.chromium.org/6111012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71337 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 12 insertions, 10 deletions

diff --git a/chrome/browser/sync/glue/sync_backend_host.cc b/chrome/browser/sync/glue/sync_backend_host.cc
index 4dafe24..ed363fc 100644
--- a/chrome/browser/sync/glue/sync_backend_host.cc
+++ b/chrome/browser/sync/glue/sync_backend_host.cc
@@ -97,12 +97,18 @@ void SyncBackendHost::Initialize(
   // when a new type is synced as the worker may already exist and you just
   // need to update routing_info_.
   registrar_.workers[GROUP_DB] = new DatabaseModelWorker();
-  registrar_.workers[GROUP_HISTORY] =
-      new HistoryModelWorker(
-          profile_->GetHistoryService(Profile::IMPLICIT_ACCESS));
   registrar_.workers[GROUP_UI] = new UIModelWorker(frontend_loop_);
   registrar_.workers[GROUP_PASSIVE] = new ModelSafeWorker();
 
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableSyncTypedUrls) || types.count(syncable::TYPED_URLS)) {
+    // TODO(tim): Bug 53916.  HistoryModelWorker crashes, so avoid adding it
+    // unless specifically requested until bug is fixed.
+    registrar_.workers[GROUP_HISTORY] =
+        new HistoryModelWorker(
+            profile_->GetHistoryService(Profile::IMPLICIT_ACCESS));
+  }
+
   PasswordStore* password_store =
       profile_->GetPasswordStore(Profile::IMPLICIT_ACCESS);
   if (password_store) {
diff --git a/chrome/browser/sync/profile_sync_service_password_unittest.cc b/chrome/browser/sync/profile_sync_service_password_unittest.cc
index dfb172b..899b40c 100644
--- a/chrome/browser/sync/profile_sync_service_password_unittest.cc
+++ b/chrome/browser/sync/profile_sync_service_password_unittest.cc
@@ -166,13 +166,6 @@ class ProfileSyncServicePasswordTest : public AbstractProfileSyncServiceTest {
       EXPECT_CALL(profile_, GetTokenService()).
           WillRepeatedly(Return(&token_service_));
 
-      // Creating model safe workers will request the history service and
-      // password store.  I couldn't manage to convince gmock that splitting up
-      // the expectations to match the class responsibilities was a good thing,
-      // so we set them all together here.
-      EXPECT_CALL(profile_, GetHistoryService(_)).
-         WillOnce(Return(static_cast<HistoryService*>(NULL)));
-
       EXPECT_CALL(profile_, GetPasswordStore(_)).
           Times(2).
           WillRepeatedly(Return(password_store_.get()));
diff --git a/chrome/browser/sync/test_profile_sync_service.h b/chrome/browser/sync/test_profile_sync_service.h
index 2615b24..ae2a331 100644
--- a/chrome/browser/sync/test_profile_sync_service.h
+++ b/chrome/browser/sync/test_profile_sync_service.h
@@ -173,6 +173,9 @@ class SyncBackendHostForProfileSyncTest : public SyncBackendHost {
   static void SetDefaultExpectationsForWorkerCreation(ProfileMock* profile) {
     EXPECT_CALL(*profile, GetPasswordStore(testing::_)).
         WillOnce(testing::Return((PasswordStore*)NULL));
+  }
+
+  static void SetHistoryServiceExpectations(ProfileMock* profile) {
     EXPECT_CALL(*profile, GetHistoryService(testing::_)).
         WillOnce(testing::Return((HistoryService*)NULL));
   }