Revert of ChannelMojo: Ensure that it always has ScopedIPCSupport

ipc/mojo/ipc_channel_mojo_host.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/mojo/ipc_channel_mojo_host.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "ipc/mojo/ipc_channel_mojo.h"
 
@@ skipping 12 matching lines @@
     : public base::RefCountedThreadSafe<ChannelMojoHost::ChannelDelegate,
                                         ChannelMojoHost::ChannelDelegateTraits>,
       public ChannelMojo::Delegate {
  public:
   explicit ChannelDelegate(
       scoped_refptr<base::SequencedTaskRunner> io_task_runner);
 
   // ChannelMojo::Delegate
   base::WeakPtr<Delegate> ToWeakPtr() override;
   void OnChannelCreated(base::WeakPtr<ChannelMojo> channel) override;
+  scoped_refptr<base::TaskRunner> GetIOTaskRunner() override;
 
   // Returns an weak ptr of ChannelDelegate instead of Delegate
   base::WeakPtr<ChannelDelegate> GetWeakPtr();
   void OnClientLaunched(base::ProcessHandle process);
   void DeleteThisSoon() const;
 
  private:
   friend class base::DeleteHelper<ChannelDelegate>;
 
   ~ChannelDelegate() override;
@@ skipping 22 matching lines @@
 ChannelMojoHost::ChannelDelegate::GetWeakPtr() {
   return weak_factory_.GetWeakPtr();
 }
 
 void ChannelMojoHost::ChannelDelegate::OnChannelCreated(
     base::WeakPtr<ChannelMojo> channel) {
   DCHECK(!channel_);
   channel_ = channel;
 }
 
+scoped_refptr<base::TaskRunner>
+ChannelMojoHost::ChannelDelegate::GetIOTaskRunner() {
+  return io_task_runner_;
+}
+
 void ChannelMojoHost::ChannelDelegate::OnClientLaunched(
     base::ProcessHandle process) {
   if (channel_)
     channel_->OnClientLaunched(process);
 }
 
 void ChannelMojoHost::ChannelDelegate::DeleteThisSoon() const {
   io_task_runner_->DeleteSoon(FROM_HERE, this);
 }
 
@@ skipping 25 matching lines @@
   return channel_delegate_.get();
 }
 
 // static
 void ChannelMojoHost::ChannelDelegateTraits::Destruct(
     const ChannelMojoHost::ChannelDelegate* ptr) {
   ptr->DeleteThisSoon();
 }
 
 }  // namespace IPC