Re-land: Mark async texture uploads as completed from the upload thread.

gpu/command_buffer/service/common_decoder.cc

Index: gpu/command_buffer/service/common_decoder.cc
diff --git a/gpu/command_buffer/service/common_decoder.cc b/gpu/command_buffer/service/common_decoder.cc
index fa97c1c2730084658740a9586a65f995ae467203..e0a6a316e2a6ea70ffa5a681a19b6b68b9197f0a 100644
--- a/gpu/command_buffer/service/common_decoder.cc
+++ b/gpu/command_buffer/service/common_decoder.cc
@@ -63,6 +63,7 @@ CommonDecoder::~CommonDecoder() {}
 void* CommonDecoder::GetAddressAndCheckSize(unsigned int shm_id,
                                             unsigned int offset,
                                             unsigned int size) {
+  CHECK(engine_);
   Buffer buffer = engine_->GetSharedMemoryBuffer(shm_id);
   if (!buffer.ptr)
     return NULL;