Remove support for "all or none" two-phase data pipe read/write.

mojo/edk/system/data_pipe_producer_dispatcher.cc

 // Copyright 2013 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 "mojo/edk/system/data_pipe_producer_dispatcher.h"
 
 #include "base/logging.h"
 #include "mojo/edk/system/data_pipe.h"
 #include "mojo/edk/system/memory.h"
 
@@ skipping 66 matching lines @@
   return data_pipe_->ProducerWriteData(
       elements, num_bytes, (flags & MOJO_WRITE_DATA_FLAG_ALL_OR_NONE));
 }
 
 MojoResult DataPipeProducerDispatcher::BeginWriteDataImplNoLock(
     UserPointer<void*> buffer,
     UserPointer<uint32_t> buffer_num_bytes,
     MojoWriteDataFlags flags) {
   mutex().AssertHeld();
 
-  return data_pipe_->ProducerBeginWriteData(
-      buffer, buffer_num_bytes, (flags & MOJO_WRITE_DATA_FLAG_ALL_OR_NONE));
+  // This flag may not be used in two-phase mode.
+  if ((flags & MOJO_WRITE_DATA_FLAG_ALL_OR_NONE))
+    return MOJO_RESULT_INVALID_ARGUMENT;
+
+  // TODO(vtl): Remove all-or-none support at lower levels.
+  return data_pipe_->ProducerBeginWriteData(buffer, buffer_num_bytes, false);
 }
 
 MojoResult DataPipeProducerDispatcher::EndWriteDataImplNoLock(
     uint32_t num_bytes_written) {
   mutex().AssertHeld();
 
   return data_pipe_->ProducerEndWriteData(num_bytes_written);
 }
 
 HandleSignalsState DataPipeProducerDispatcher::GetHandleSignalsStateImplNoLock()
@@ skipping 40 matching lines @@
   return rv;
 }
 
 bool DataPipeProducerDispatcher::IsBusyNoLock() const {
   mutex().AssertHeld();
   return data_pipe_->ProducerIsBusy();
 }
 
 }  // namespace system
 }  // namespace mojo