Use system constants instead of NULL for unset PID.

content/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/gpu/gpu_channel.h"
 
 #include "base/command_line.h"
 #include "base/process_util.h"
 #include "base/string_util.h"
 #include "content/common/child_process.h"
 #include "content/common/content_client.h"
 #include "content/common/content_switches.h"
 #include "content/common/gpu_messages.h"
 #include "content/gpu/gpu_render_thread.h"
 #include "content/gpu/gpu_video_service.h"
 
 #if defined(OS_POSIX)
 #include "ipc/ipc_channel_posix.h"
 #endif
 
 GpuChannel::GpuChannel(GpuRenderThread* gpu_render_thread,
                        GpuWatchdogThread* gpu_watchdog_thread,
                        int renderer_id)
     : gpu_render_thread_(gpu_render_thread),
       renderer_id_(renderer_id),
-      renderer_process_(NULL),
-      renderer_pid_(NULL),
+      renderer_process_(base::kNullProcessHandle),
+      renderer_pid_(base::kNullProcessId),
       watchdog_thread_(gpu_watchdog_thread) {
   DCHECK(gpu_render_thread);
   DCHECK(renderer_id);
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
   log_messages_ = command_line->HasSwitch(switches::kLogPluginMessages);
   disallowed_extensions_.multisampling =
       command_line->HasSwitch(switches::kDisableGLMultisampling);
 }
 
 GpuChannel::~GpuChannel() {
@@ skipping 222 matching lines @@
 
 #if defined(OS_POSIX)
 int GpuChannel::GetRendererFileDescriptor() {
   int fd = -1;
   if (channel_.get()) {
     fd = channel_->GetClientFileDescriptor();
   }
   return fd;
 }
 #endif  // defined(OS_POSIX)
-