Remove the task tracking stuff in the bindings.

mojo/common/BUILD.gn

 # Copyright 2014 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.
 
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 
 source_set("common") {
   sources = [
     "binding_set.h",
     "interface_ptr_set.h",
     "strong_binding_set.h",
-    "task_tracker.cc",
-    "task_tracker.h",
   ]
 
   deps = [
     "//base",
     "//mojo/public/cpp/bindings",
   ]
 }
 
 source_set("tests") {
   testonly = true
 
   sources = [
     "binding_set_unittest.cc",
     "callback_binding_unittest.cc",
     "interface_ptr_set_unittest.cc",
     "strong_binding_set_unittest.cc",
-    "task_tracker_unittest.cc",
   ]
 
   deps = [
     ":common",
     ":test_interfaces",
     "//base",
     "//mojo/message_pump",
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/bindings:callback",
     "//mojo/public/cpp/system",
@@ skipping 29 matching lines @@
     "tracing_impl.h",
   ]
 
   deps = [
     "//base",
     "//mojo/public/cpp/application",
     "//mojo/public/cpp/bindings",
     "//mojo/services/tracing/interfaces",
   ]
 }