Revert "Fix a ton of compiler warnings."

chrome/common/child_process_host.cc

 // Copyright (c) 2009 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 "chrome/common/child_process_host.h"
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/logging.h"
@@ skipping 188 matching lines @@
   bool did_crash = base::DidProcessCrash(NULL, handle());
   if (did_crash) {
     // Report that this child process crashed.
     Notify(NotificationType::CHILD_PROCESS_CRASHED);
   }
   // Notify in the main loop of the disconnection.
   Notify(NotificationType::CHILD_PROCESS_HOST_DISCONNECTED);
 
   // On POSIX, once we've called DidProcessCrash, handle() is no longer
   // valid.  Ensure the destructor doesn't try to use it.
-  set_handle(0);
+  set_handle(NULL);
 
   delete this;
 }
 
 ChildProcessHost::ListenerHook::ListenerHook(ChildProcessHost* host)
     : host_(host) {
 }
 
 void ChildProcessHost::ListenerHook::OnMessageReceived(
     const IPC::Message& msg) {
@@ skipping 79 matching lines @@
 
     return *iterator_;
   } while (true);
 
   return NULL;
 }
 
 bool ChildProcessHost::Iterator::Done() {
   return iterator_ == Singleton<ChildProcessList>::get()->end();
 }