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

content/common/gpu/gpu_channel.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.
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
 #include "content/common/gpu/gpu_channel.h"
 
@@ skipping 399 matching lines @@
 }
 
 void GpuChannel::OnCloseChannel() {
   gpu_channel_manager_->RemoveChannel(renderer_id_);
   // At this point "this" is deleted!
 }
 
 bool GpuChannel::Init(base::MessageLoopProxy* io_message_loop,
                       base::WaitableEvent* shutdown_event) {
   // Check whether we're already initialized.
-  if (channel_.get())
+  if (channel_.get()) {
+    // TODO(xhwang): Added to investigate crbug.com/95732. Clean up after fixed.
+    CHECK(false);
     return true;
+  }
 
   // Map renderer ID to a (single) channel to that process.
   std::string channel_name = GetChannelName();
   channel_.reset(new IPC::SyncChannel(
       channel_name,
       IPC::Channel::MODE_SERVER,
       this,
       io_message_loop,
       false,
       shutdown_event));
@@ skipping 18 matching lines @@
 
 #if defined(OS_POSIX)
 int GpuChannel::TakeRendererFileDescriptor() {
   if (!channel_.get()) {
     NOTREACHED();
     return -1;
   }
   return channel_->TakeClientFileDescriptor();
 }
 #endif  // defined(OS_POSIX)