Add some histograms to the D-Bus library:

dbus/bus.cc

 // Copyright (c) 2011 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.
 //
 // TODO(satorux):
 // - Handle "disconnected" signal.
-// - Collect metrics (ex. # of method calls, method call time, etc.)
 
 #include "dbus/bus.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time.h"
@@ skipping 705 matching lines @@
 }
 
 void Bus::OnDispatchStatusChangedThunk(DBusConnection* connection,
                                        DBusDispatchStatus status,
                                        void* data) {
   Bus* self = static_cast<Bus*>(data);
   return self->OnDispatchStatusChanged(connection, status);
 }
 
 }  // namespace dbus