PPAPI/NaCl: Fix IPC proxy build; pthread_t changed

base/threading/platform_thread_posix.cc

 // Copyright (c) 2012 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/threading/platform_thread.h"
 
 #include <errno.h>
 #include <sched.h>
 
 #include "base/lazy_instance.h"
@@ skipping 142 matching lines @@
 }  // namespace
 
 // static
 PlatformThreadId PlatformThread::CurrentId() {
   // Pthreads doesn't have the concept of a thread ID, so we have to reach down
   // into the kernel.
 #if defined(OS_LINUX)
   return syscall(__NR_gettid);
 #elif defined(OS_ANDROID)
   return gettid();
-#elif defined(OS_NACL) || defined(OS_SOLARIS)
+#elif defined(OS_SOLARIS)
   return pthread_self();
+#elif defined(OS_NACL)
+  // Pointers are 32-bits in NaCl.

[Mark Seaborn, 2012/05/22 16:39:39]

You might also comment that we're assuming nacl-newlib's pthread implementation.
 NaCl itself does not specify that pthread_t is a pointer.

+  return reinterpret_cast<int32>(pthread_self());

[Mark Seaborn, 2012/05/22 16:39:39]

FYI, this would break again if nacl-newlib's libpthread changed the type back to
int, because an int->int reinterpret_cast is rejected by some compilers.  A
C-style cast would avoid that problem.

 #elif defined(OS_POSIX)
   return reinterpret_cast<int64>(pthread_self());
 #endif
 }
 
 // static
 void PlatformThread::YieldCurrentThread() {
   sched_yield();
 }
 
@@ skipping 104 matching lines @@
 #if !defined(OS_MACOSX)
 // Mac OS X uses lower-level mach APIs.
 
 // static
 void PlatformThread::SetThreadPriority(PlatformThreadHandle, ThreadPriority) {
   // TODO(crogers): Implement, see http://crbug.com/116172
 }
 #endif
 
 }  // namespace base