Use the location where FileDescriptorWatcher is created to track the libevent handlers

base/message_loop/message_loop_unittest.cc

 // Copyright 2013 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 <stddef.h>
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 721 matching lines @@
 
   // Create a file descriptor.  Doesn't need to be readable or writable,
   // as we don't need to actually get any notifications.
   // pipe() is just the easiest way to do it.
   int pipefds[2];
   int err = pipe(pipefds);
   ASSERT_EQ(0, err);
   int fd = pipefds[1];
   {
     // Arrange for controller to live longer than message loop.
-    MessageLoopForIO::FileDescriptorWatcher controller;
+    MessageLoopForIO::FileDescriptorWatcher controller(FROM_HERE);
     {
       MessageLoopForIO message_loop;
 
       QuitDelegate delegate;
       message_loop.WatchFileDescriptor(fd,
           true, MessageLoopForIO::WATCH_WRITE, &controller, &delegate);
       // and don't run the message loop, just destroy it.
     }
   }
   if (IGNORE_EINTR(close(pipefds[0])) < 0)
     PLOG(ERROR) << "close";
   if (IGNORE_EINTR(close(pipefds[1])) < 0)
     PLOG(ERROR) << "close";
 }
 
 TEST(MessageLoopTest, FileDescriptorWatcherDoubleStop) {
   // Verify that it's ok to call StopWatchingFileDescriptor().
   // (Errors only showed up in valgrind.)
   int pipefds[2];
   int err = pipe(pipefds);
   ASSERT_EQ(0, err);
   int fd = pipefds[1];
   {
     // Arrange for message loop to live longer than controller.
     MessageLoopForIO message_loop;
     {
-      MessageLoopForIO::FileDescriptorWatcher controller;
+      MessageLoopForIO::FileDescriptorWatcher controller(FROM_HERE);
 
       QuitDelegate delegate;
       message_loop.WatchFileDescriptor(fd,
           true, MessageLoopForIO::WATCH_WRITE, &controller, &delegate);
       controller.StopWatchingFileDescriptor();
     }
   }
   if (IGNORE_EINTR(close(pipefds[0])) < 0)
     PLOG(ERROR) << "close";
   if (IGNORE_EINTR(close(pipefds[1])) < 0)
@@ skipping 241 matching lines @@
 
   {
     std::string kThreadName("bar");
     base::Thread thread(kThreadName);
     ASSERT_TRUE(thread.StartAndWaitForTesting());
     EXPECT_EQ(kThreadName, thread.message_loop()->GetThreadName());
   }
 }
 
 }  // namespace base