Replace PluginThreadTaskRunner with a simpler MainPluginThreadTaskRunner.

remoting/client/plugin/pepper_plugin_thread_delegate.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.
-
-#include "remoting/client/plugin/pepper_plugin_thread_delegate.h"
-
-#include "ppapi/cpp/completion_callback.h"
-#include "ppapi/cpp/module.h"
-
-namespace remoting {
-
-PepperPluginThreadDelegate::PepperPluginThreadDelegate()
-    : core_(pp::Module::Get()->core()) {
-}
-
-PepperPluginThreadDelegate::~PepperPluginThreadDelegate() { }
-
-bool PepperPluginThreadDelegate::RunOnPluginThread(
-    base::TimeDelta delay, void(CDECL function)(void*), void* data) {
-  // It is safe to cast |function| to PP_CompletionCallback_Func,
-  // which is defined as void(*)(void*, int). The callee will just
-  // ignore the last argument. The only case when it may be unsafe is
-  // with VS when default calling convention is set to __stdcall, but
-  // this code will not typecheck in that case.
-  core_->CallOnMainThread(
-      delay.InMilliseconds(), pp::CompletionCallback(
-          reinterpret_cast<PP_CompletionCallback_Func>(function), data), 0);
-  return true;
-}
-
-}  // namespace remoting