IPC: Delete thread-safe send support

content/child/indexed_db/webidbcursor_impl_unittest.cc

Index: content/child/indexed_db/webidbcursor_impl_unittest.cc
diff --git a/content/child/indexed_db/webidbcursor_impl_unittest.cc b/content/child/indexed_db/webidbcursor_impl_unittest.cc
index da4aee4d14183fe3dbefd476b8df5b6344388898..83b2110ac14140f1c4b927e7aad776f6992bc806 100644
--- a/content/child/indexed_db/webidbcursor_impl_unittest.cc
+++ b/content/child/indexed_db/webidbcursor_impl_unittest.cc
@@ -124,8 +124,7 @@ class MockContinueCallbacks : public StrictMock<MockWebIDBCallbacks> {
 
 class MockSyncMessageFilter : public IPC::SyncMessageFilter {
  public:
-  MockSyncMessageFilter()
-      : SyncMessageFilter(nullptr, false /* is_channel_send_thread_safe */) {}
+  MockSyncMessageFilter() : SyncMessageFilter(nullptr) {}
 
  private:
   ~MockSyncMessageFilter() override {}