Abort sync cycles when download step fails

sync/test/engine/mock_connection_manager.cc

Index: sync/test/engine/mock_connection_manager.cc
diff --git a/sync/test/engine/mock_connection_manager.cc b/sync/test/engine/mock_connection_manager.cc
index ab95bce6f2afe92e3fb39c5b03603b7034417f68..166b27ac4142976fcb66e05085bdbc2eebe6aa24 100644
--- a/sync/test/engine/mock_connection_manager.cc
+++ b/sync/test/engine/mock_connection_manager.cc
@@ -48,7 +48,7 @@ MockConnectionManager::MockConnectionManager(syncable::Directory* directory)
       store_birthday_sent_(false),
       client_stuck_(false),
       commit_time_rename_prepended_string_(""),
-      fail_next_postbuffer_(false),
+      countdown_to_postbuffer_fail_(0),
       directory_(directory),
       mid_commit_observer_(NULL),
       throttling_(false),
@@ -111,8 +111,9 @@ bool MockConnectionManager::PostBufferToPath(PostBufferParams* params,
     InvalidateAndClearAuthToken();
   }
 
-  if (fail_next_postbuffer_) {
-    fail_next_postbuffer_ = false;
+  if (--countdown_to_postbuffer_fail_ == 0) {
+    // Fail as countdown hits zero.
+    params->response.server_status = HttpResponse::SYNC_SERVER_ERROR;
     return false;
   }
 
@@ -564,30 +565,6 @@ const CommitResponse& MockConnectionManager::last_commit_response() const {
   return *commit_responses_->back();
 }
 
-void MockConnectionManager::ThrottleNextRequest(
-    ResponseCodeOverrideRequestor* visitor) {
-  base::AutoLock lock(response_code_override_lock_);
-  throttling_ = true;
-  if (visitor)
-    visitor->OnOverrideComplete();
-}
-
-void MockConnectionManager::FailWithAuthInvalid(
-    ResponseCodeOverrideRequestor* visitor) {
-  base::AutoLock lock(response_code_override_lock_);
-  fail_with_auth_invalid_ = true;
-  if (visitor)
-    visitor->OnOverrideComplete();
-}
-
-void MockConnectionManager::StopFailingWithAuthInvalid(
-    ResponseCodeOverrideRequestor* visitor) {
-  base::AutoLock lock(response_code_override_lock_);
-  fail_with_auth_invalid_ = false;
-  if (visitor)
-    visitor->OnOverrideComplete();
-}
-
 bool MockConnectionManager::IsModelTypePresentInSpecifics(
     const google::protobuf::RepeatedPtrField<
         sync_pb::DataTypeProgressMarker>& filter,