Revert "Update mojo sdk to rev 1dc8a9a5db73d3718d99917fadf31f5fb2ebad4f"

third_party/mojo/src/mojo/edk/system/raw_channel.cc

Index: third_party/mojo/src/mojo/edk/system/raw_channel.cc
diff --git a/third_party/mojo/src/mojo/edk/system/raw_channel.cc b/third_party/mojo/src/mojo/edk/system/raw_channel.cc
index 4cf7c02f0cc6cdeec6855fdcc7f24dfde57fff9b..383a743175b55e53057766bf9f0fbef851ec685c 100644
--- a/third_party/mojo/src/mojo/edk/system/raw_channel.cc
+++ b/third_party/mojo/src/mojo/edk/system/raw_channel.cc
@@ -87,6 +87,7 @@ void RawChannel::WriteBuffer::GetPlatformHandlesToSend(
   if (serialized_platform_handle_size_ > 0) {
     size_t serialization_data_offset =
         transport_data->platform_handle_table_offset();
+    DCHECK_GT(serialization_data_offset, 0u);
     serialization_data_offset +=
         platform_handles_offset_ * serialized_platform_handle_size_;
     *serialization_data = static_cast<char*>(transport_data->buffer()) +