Re-land: cc: Use worker context for one-copy tile initialization.

gpu/command_buffer/client/cmd_buffer_helper.cc

 // Copyright (c) 2012 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.
 
 // This file contains the implementation of the command buffer helper class.
 
 #include "gpu/command_buffer/client/cmd_buffer_helper.h"
 
 #include <algorithm>
 #include "base/logging.h"
@@ skipping 180 matching lines @@
 // error is set.
 bool CommandBufferHelper::Finish() {
   TRACE_EVENT0("gpu", "CommandBufferHelper::Finish");
   if (!usable()) {
     return false;
   }
   // If there is no work just exit.
   if (put_ == get_offset()) {
     return true;
   }
-  DCHECK(HaveRingBuffer());
+  DCHECK(HaveRingBuffer() ||
+         error::IsError(command_buffer_->GetLastState().error));

[Ken Russell (switch to Gerrit), 2015/08/17 19:59:07]

If the error::IsError case is hit in this DCHECK, will the code below work
correctly? In particular, the call to WaitForGetOffsetInRange? Will callers
notice the failures?

[piman, 2015/08/17 22:29:55]

WaitForGetOffsetInRange will return false immediately.

   Flush();
   if (!WaitForGetOffsetInRange(put_, put_))
     return false;
   DCHECK_EQ(get_offset(), put_);
 
   CalcImmediateEntries(0);
 
   return true;
 }
 
@@ skipping 90 matching lines @@
       if (!WaitForGetOffsetInRange(put_ + count + 1, put_))
         return;
       CalcImmediateEntries(count);
       DCHECK_GE(immediate_entry_count_, count);
     }
   }
 }
 
 
 }  // namespace gpu