Tag some of Mojo heap allocations for the heap profiler.

mojo/common/data_pipe_drainer.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 "mojo/common/data_pipe_drainer.h"
 
 #include <stdint.h>
 
 #include <utility>
 
 #include "base/bind.h"
 
 namespace mojo {
 namespace common {
 
 DataPipeDrainer::DataPipeDrainer(Client* client,
                                  mojo::ScopedDataPipeConsumerHandle source)
-    : client_(client), source_(std::move(source)), weak_factory_(this) {
+    : client_(client),
+      source_(std::move(source)),
+      handle_watcher_(FROM_HERE),
+      weak_factory_(this) {
   DCHECK(client_);
   handle_watcher_.Start(
       source_.get(), MOJO_HANDLE_SIGNAL_READABLE,
       base::Bind(&DataPipeDrainer::WaitComplete, weak_factory_.GetWeakPtr()));
 }
 
 DataPipeDrainer::~DataPipeDrainer() {}
 
 void DataPipeDrainer::ReadData() {
   const void* buffer = nullptr;
   uint32_t num_bytes = 0;
   MojoResult rv = BeginReadDataRaw(source_.get(), &buffer, &num_bytes,
                                    MOJO_READ_DATA_FLAG_NONE);
   if (rv == MOJO_RESULT_OK) {
     client_->OnDataAvailable(buffer, num_bytes);
     EndReadDataRaw(source_.get(), num_bytes);
   } else if (rv == MOJO_RESULT_FAILED_PRECONDITION) {
     client_->OnDataComplete();
   } else if (rv != MOJO_RESULT_SHOULD_WAIT) {
     DCHECK(false) << "Unhandled MojoResult: " << rv;
   }
 }
 
 void DataPipeDrainer::WaitComplete(MojoResult result) {
   ReadData();
 }
 
 }  // namespace common
 }  // namespace mojo