Add more CHECK in GPU and NPAPI process on invalid file descriptors

content/common/gpu/gpu_channel_manager.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 "content/common/gpu/gpu_channel_manager.h"
 
 #include "base/bind.h"
 #include "content/common/child_thread.h"
 #include "content/common/gpu/gpu_channel.h"
 #include "content/common/gpu/gpu_messages.h"
@@ skipping 59 matching lines @@
 bool GpuChannelManager::Send(IPC::Message* msg) {
   return gpu_child_thread_->Send(msg);
 }
 
 void GpuChannelManager::OnEstablishChannel(int renderer_id) {
   scoped_refptr<GpuChannel> channel;
   IPC::ChannelHandle channel_handle;
   content::GPUInfo gpu_info;
 
   GpuChannelMap::const_iterator iter = gpu_channels_.find(renderer_id);
-  if (iter == gpu_channels_.end())
+  if (iter == gpu_channels_.end()) {
     channel = new GpuChannel(this, watchdog_, renderer_id, false);
-  else
+  } else {
+    // TODO(xhwang): Added to investigate crbug.com/95732. Clean up after fixed.
+    CHECK(false);
     channel = iter->second;
+  }
 
   DCHECK(channel != NULL);
 
   if (channel->Init(io_message_loop_, shutdown_event_))
     gpu_channels_[renderer_id] = channel;
   else
     channel = NULL;
 
   if (channel.get()) {
     channel_handle.name = channel->GetChannelName();
@@ skipping 47 matching lines @@
 void GpuChannelManager::LoseAllContexts() {
   MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&GpuChannelManager::OnLoseAllContexts,
                  weak_factory_.GetWeakPtr()));
 }
 
 void GpuChannelManager::OnLoseAllContexts() {
   gpu_channels_.clear();
 }