[SyncFS] Promote demoted changes in default remote side backend

BUG=401853

Review URL: https://codereview.chromium.org/453673003

Cr-Commit-Position: refs/heads/master@{#289135}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289135 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/sync_file_system/sync_file_system_service.cc

@@ -368,8 +368,11 @@ void SyncFileSystemService::OnSyncIdle() {
            local_sync_runners_.begin();
        iter != local_sync_runners_.end(); ++iter)
     local_changes += (*iter)->pending_changes();
-  if (local_changes == 0 && v2_remote_service_)
-    v2_remote_service_->PromoteDemotedChanges(NoopClosure());
+  if (local_changes == 0) {
+    remote_service_->PromoteDemotedChanges(NoopClosure());
+    if (v2_remote_service_)
+      v2_remote_service_->PromoteDemotedChanges(NoopClosure());
+  }
 }
 
 SyncServiceState SyncFileSystemService::GetSyncServiceState() {

chrome/browser/sync_file_system/sync_file_system_service_unittest.cc

@@ -119,6 +119,11 @@ ACTION_P2(MockSyncFileCallback, status, url) {
       FROM_HERE, base::Bind(arg0, status, url));
 }
 
+ACTION(InvokeCompletionClosure) {
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(arg0));
+}
+
 class SyncFileSystemServiceTest : public testing::Test {
  protected:
   SyncFileSystemServiceTest()
@@ -349,6 +354,9 @@ TEST_F(SyncFileSystemServiceTest, SimpleLocalSyncFlow) {
               ApplyLocalChange(change, _, _, kFile, _))
       .WillOnce(MockStatusCallback(SYNC_STATUS_OK));
 
+  EXPECT_CALL(*mock_remote_service(), PromoteDemotedChanges(_))
+      .WillRepeatedly(InvokeCompletionClosure());
+
   EXPECT_EQ(base::File::FILE_OK, file_system_->CreateFile(kFile));
 
   run_loop.Run();
@@ -398,6 +406,9 @@ TEST_F(SyncFileSystemServiceTest, SimpleSyncFlowWithFileBusy) {
         .WillOnce(InvokeWithoutArgs(&run_loop, &base::RunLoop::Quit));
   }
 
+  EXPECT_CALL(*mock_remote_service(), PromoteDemotedChanges(_))
+      .WillRepeatedly(InvokeCompletionClosure());
+
   // We might also see an activity for local sync as we're going to make
   // a local write operation on kFile.
   EXPECT_CALL(*mock_local_change_processor(),