Add a comment about a leak/suppression.

chrome/browser/browser_main_posix.cc

 // Copyright (c) 2010 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/browser/browser_main_posix.h"
 
 #include <errno.h>
 #include <signal.h>
 #include <sys/resource.h>
 
@@ skipping 191 matching lines @@
 
 void BrowserMainPartsPosix::PostMainMessageLoopStart() {
   int pipefd[2];
   int ret = pipe(pipefd);
   if (ret < 0) {
     PLOG(DFATAL) << "Failed to create pipe";
   } else {
     g_shutdown_pipe_read_fd = pipefd[0];
     g_shutdown_pipe_write_fd = pipefd[1];
     const size_t kShutdownDetectorThreadStackSize = 4096;
+    // TODO(viettrungluu,willchan): crbug.com/29675 - This currently leaks, so
+    // if you change this, you'll probably need to change the suppression.
     if (!PlatformThread::CreateNonJoinable(
         kShutdownDetectorThreadStackSize,
         new ShutdownDetector(g_shutdown_pipe_read_fd))) {
       LOG(DFATAL) << "Failed to create shutdown detector task.";
     }
   }
 }
 
 // Mac further subclasses BrowserMainPartsPosix
 #if !defined(OS_MACOSX)
 // static
 BrowserMainParts* BrowserMainParts::CreateBrowserMainParts(
     const MainFunctionParams& parameters) {
   return new BrowserMainPartsPosix(parameters);
 }
 #endif  // !defined(OS_MACOSX)