Added a way for sync point clients to issue out of order waits.

components/mus/gles2/command_buffer_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/gles2/command_buffer_impl.h"
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "components/mus/gles2/command_buffer_driver.h"
@@ skipping 196 matching lines @@
 
 bool CommandBufferImpl::FlushHelper(int32_t put_offset,
                                     uint32_t order_num) {
   DCHECK(driver_->IsScheduled());
   driver_->sync_point_order_data()->BeginProcessingOrderNumber(order_num);
   driver_->Flush(put_offset);
 
   // Return false if the Flush is not finished, so the CommandBufferTaskRunner
   // will not remove this task from the task queue.
   const bool complete = !driver_->HasUnprocessedCommands();
-  if (complete)
+  if (!complete)
+    driver_->sync_point_order_data()->PauseProcessingOrderNumber(order_num);
+  else
     driver_->sync_point_order_data()->FinishProcessingOrderNumber(order_num);
   return complete;
 }
 
 bool CommandBufferImpl::MakeProgressHelper(
     int32_t last_get_offset,
     const base::Callback<void(mojom::CommandBufferStatePtr)>& callback) {
   DCHECK(driver_->IsScheduled());
   mojom::CommandBufferStatePtr state =
       mojom::CommandBufferState::From(driver_->GetLastState());
@@ skipping 55 matching lines @@
       driver_.get(),
       base::Bind(&CommandBufferImpl::DeleteHelper, base::Unretained(this)));
 }
 
 bool CommandBufferImpl::DeleteHelper() {
   delete this;
   return true;
 }
 
 }  // namespace mus