Add stats collection for telemetry startup.warm.blank_page test.

mojo/services/tracing/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/mojo_application.gni")
-import("//third_party/mojo/src/mojo/public/tools/bindings/mojom.gni")
 
 mojo_native_application("tracing") {
   sources = [
     "main.cc",
   ]
 
   deps = [
     ":lib",
     "//mojo/application/public/cpp",
     "//third_party/mojo/src/mojo/public/cpp/system",
   ]
 }
 
-mojom("bindings") {
-  sources = [
-    "tracing.mojom",
-  ]
-}
-
 source_set("lib") {
   sources = [
     "trace_data_sink.cc",
     "trace_data_sink.h",
     "tracing_app.cc",
     "tracing_app.h",
   ]
 
   deps = [
-    ":bindings",
     "//base",
     "//mojo/application/public/cpp",
     "//mojo/common:common_base",
+    "//mojo/services/tracing/public/interfaces",
   ]
 }