Use PlatformThreadId, not int when dealing with thread ids.

base/platform_thread_win.cc

 // Copyright (c) 2006-2008 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 "base/platform_thread.h"
 
 #include "base/logging.h"
 #include "base/win_util.h"
 
 namespace {
@@ skipping 12 matching lines @@
 DWORD __stdcall ThreadFunc(void* closure) {
   PlatformThread::Delegate* delegate =
       static_cast<PlatformThread::Delegate*>(closure);
   delegate->ThreadMain(); 
   return NULL;
 }
 
 }  // namespace
 
 // static
-int PlatformThread::CurrentId() {
+PlatformThreadId PlatformThread::CurrentId() {
   return GetCurrentThreadId();
 }
 
 // static
 void PlatformThread::YieldCurrentThread() {
   ::Sleep(0);
 }
 
 // static
 void PlatformThread::Sleep(int duration_ms) {
@@ skipping 44 matching lines @@
 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
   DCHECK(thread_handle);
 
   // Wait for the thread to exit.  It should already have terminated but make
   // sure this assumption is valid.
   DWORD result = WaitForSingleObject(thread_handle, INFINITE);
   DCHECK_EQ(WAIT_OBJECT_0, result);
 
   CloseHandle(thread_handle);
 }