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

chrome/browser/chrome_browser_main_extra_parts_exo.cc

 // Copyright 2015 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/chrome_browser_main_extra_parts_exo.h"
 
 #include "base/memory/ptr_util.h"
 
 #if defined(USE_GLIB)
 #include <glib.h>
@@ skipping 72 matching lines @@
 
   // The GLib event source for wayland events.
   GLibWaylandSource* wayland_source_;
 
   DISALLOW_COPY_AND_ASSIGN(WaylandWatcher);
 };
 #else
 class ChromeBrowserMainExtraPartsExo::WaylandWatcher
     : public base::MessagePumpLibevent::Watcher {
  public:
-  explicit WaylandWatcher(exo::wayland::Server* server) : server_(server) {
+  explicit WaylandWatcher(exo::wayland::Server* server)
+      : controller_(FROM_HERE), server_(server) {
     base::MessageLoopForUI::current()->WatchFileDescriptor(
         server_->GetFileDescriptor(),
         true,  // persistent
         base::MessagePumpLibevent::WATCH_READ, &controller_, this);
   }
 
   // base::MessagePumpLibevent::Watcher:
   void OnFileCanReadWithoutBlocking(int fd) override {
     server_->Dispatch(base::TimeDelta());
     server_->Flush();
@@ skipping 33 matching lines @@
 }
 
 void ChromeBrowserMainExtraPartsExo::PostMainMessageLoopRun() {
   wayland_watcher_.reset();
   wayland_server_.reset();
   if (wm_helper_) {
     exo::WMHelper::SetInstance(nullptr);
     wm_helper_.reset();
   }
 }