Reland http://codereview.chromium.org/7648033

ppapi/proxy/plugin_dispatcher.cc

 // Copyright (c) 2011 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 "ppapi/proxy/plugin_dispatcher.h"
 
 #include <map>
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
@@ skipping 91 matching lines @@
   channel()->AddFilter(
       new PluginMessageFilter(delegate->GetGloballySeenInstanceIDSet()));
   return true;
 }
 
 bool PluginDispatcher::IsPlugin() const {
   return true;
 }
 
 bool PluginDispatcher::Send(IPC::Message* msg) {
-  DCHECK(MessageLoop::current());
   TRACE_EVENT2("ppapi proxy", "PluginDispatcher::Send",
                "Class", IPC_MESSAGE_ID_CLASS(msg->type()),
                "Line", IPC_MESSAGE_ID_LINE(msg->type()));
   // We always want plugin->renderer messages to arrive in-order. If some sync
   // and some async messages are send in response to a synchronous
   // renderer->plugin call, the sync reply will be processed before the async
   // reply, and everything will be confused.
   //
   // Allowing all async messages to unblock the renderer means more reentrancy
   // there but gives correct ordering.
@@ skipping 184 matching lines @@
   // once they're set. The user will have to restart to get new font prefs
   // propogated to plugins.
   if (!received_preferences_) {
     received_preferences_ = true;
     preferences_ = prefs;
   }
 }
 
 }  // namespace proxy
 }  // namespace ppapi