IPC: Relax thread constraints on Channel-associated send

ipc/ipc_mojo_bootstrap.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 "ipc/ipc_mojo_bootstrap.h"
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
@@ skipping 466 matching lines @@
 
   bool SendMessage(mojo::Message* message) {
     if (task_runner_->BelongsToCurrentThread()) {
       DCHECK(thread_checker_.CalledOnValidThread());
       if (!connector_ || paused_) {
         outgoing_messages_.emplace_back(std::move(*message));
         return true;
       }
       return connector_->Accept(message);
     } else {
-      // We always post tasks to the master endpoint thread when called from the
-      // proxy thread in order to simulate IPC::ChannelProxy::Send behavior.
-      DCHECK(proxy_task_runner_->BelongsToCurrentThread());
+      // We always post tasks to the master endpoint thread when called from
+      // other threads in order to simulate IPC::ChannelProxy::Send behavior.
       task_runner_->PostTask(
           FROM_HERE,
           base::Bind(
               &ChannelAssociatedGroupController::SendMessageOnMasterThread,
               this, base::Passed(message)));
       return true;
     }
   }
 
   void SendMessageOnMasterThread(mojo::Message message) {
@@ skipping 343 matching lines @@
     Channel::Mode mode,
     Delegate* delegate,
     const scoped_refptr<base::SingleThreadTaskRunner>& ipc_task_runner) {
   return base::MakeUnique<MojoBootstrapImpl>(
       std::move(handle), delegate,
       new ChannelAssociatedGroupController(mode == Channel::MODE_SERVER,
                                            ipc_task_runner));
 }
 
 }  // namespace IPC