Make flow event traces disabled-by-default, and rename "ipc" and "task" categories to "toplevel"

base/message_loop/message_pump_gtk.cc

 // Copyright (c) 2012 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/message_loop/message_pump_gtk.h"
 
 #include <gtk/gtk.h>
 #include <gdk/gdkx.h>
 
 #include "base/debug/trace_event.h"
@@ skipping 53 matching lines @@
 MessagePumpGtk::MessagePumpGtk() : MessagePumpGlib() {
   gdk_event_handler_set(&EventDispatcher, this, NULL);
 }
 
 MessagePumpGtk::~MessagePumpGtk() {
   gdk_event_handler_set(reinterpret_cast<GdkEventFunc>(gtk_main_do_event),
                         this, NULL);
 }
 
 void MessagePumpGtk::DispatchEvents(GdkEvent* event) {
-  UNSHIPPED_TRACE_EVENT1("task", "MessagePumpGtk::DispatchEvents",
+  UNSHIPPED_TRACE_EVENT1("toplevel", "MessagePumpGtk::DispatchEvents",
                          "type", EventToTypeString(event));
 
   WillProcessEvent(event);
   gtk_main_do_event(event);
   DidProcessEvent(event);
 }
 
 // static
 Display* MessagePumpGtk::GetDefaultXDisplay() {
   static GdkDisplay* display = gdk_display_get_default();
@@ skipping 26 matching lines @@
                     DidProcessEvent(event));
 }
 
 // static
 void MessagePumpGtk::EventDispatcher(GdkEvent* event, gpointer data) {
   MessagePumpGtk* message_pump = reinterpret_cast<MessagePumpGtk*>(data);
   message_pump->DispatchEvents(event);
 }
 
 }  // namespace base