Add/improve a bunch of comments...

base/tracked_objects.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 "base/tracked_objects.h"
 
 #include <math.h>
 
 #include "base/format_macros.h"
 #include "base/message_loop.h"
@@ skipping 434 matching lines @@
         FROM_HERE, new RunTheStatic(function, completion_handle, counter));
 
   // Also run Task on our thread.
   RunTheStatic local_task(function, completion_handle, counter);
   local_task.Run();
 
   WaitForSingleObject(completion_handle, INFINITE);
   int ret_val = CloseHandle(completion_handle);
   DCHECK(ret_val);
 }
-#endif
+#endif  // OS_WIN
 
 // static
 bool ThreadData::StartTracking(bool status) {
 #ifndef TRACK_ALL_TASK_OBJECTS
   return false;  // Not compiled in.
 #endif
 
   if (!status) {
     base::AutoLock lock(list_lock_);
     DCHECK(status_ == ACTIVE || status_ == SHUTDOWN);
@@ skipping 582 matching lines @@
                         (combined_selectors_ & BIRTH_THREAD) ? "*" :
                           sample.birth().birth_thread()->ThreadName().c_str(),
                         (combined_selectors_ & DEATH_THREAD) ? "*" :
                           sample.DeathThreadName().c_str());
   sample.birth().location().Write(!(combined_selectors_ & BIRTH_FILE),
                                   !(combined_selectors_ & BIRTH_FUNCTION),
                                   output);
 }
 
 }  // namespace tracked_objects