Enable startup tracing from command line flags in components/tracing

components/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("//testing/test.gni")
 import("//third_party/protobuf/proto_library.gni")
 
 component("tracing") {
   sources = [
     "child/child_memory_dump_manager_delegate_impl.cc",
@@ skipping 32 matching lines @@
     "//components/tracing/proto:protos",
   ]
 
   if (is_nacl) {
     sources -= [ "common/process_metrics_memory_dump_provider.cc" ]
   }
 }
 
 component("startup_tracing") {
   sources = [
-    "browser/trace_config_file.cc",
-    "browser/trace_config_file.h",
+    "common/trace_config_file.cc",
+    "common/trace_config_file.h",
+    "common/trace_startup.cc",
+    "common/trace_startup.h",
     "common/trace_to_console.cc",
     "common/trace_to_console.h",
     "common/tracing_switches.cc",
     "common/tracing_switches.h",
     "tracing_export.h",
   ]
 
   defines = [ "TRACING_IMPLEMENTATION" ]
 
   deps = [
@@ skipping 41 matching lines @@
     ":proto_zero_testing_messages",
     ":tracing",
     "//base/test:test_support",
     "//components/tracing/proto:golden_protos_for_tests",
     "//ipc",
     "//testing/gmock:gmock",
     "//testing/gtest",
   ]
 
   if (!is_android) {
-    sources += [ "browser/trace_config_file_unittest.cc" ]
+    sources += [ "common/trace_config_file_unittest.cc" ]
     deps += [ ":startup_tracing" ]
   }
 }
 
 test("tracing_perftests") {
   sources = [
     "test/perf_test_helpers.cc",
     "test/perf_test_helpers.h",
     "test/trace_event_perftest.cc",
   ]
@@ skipping 10 matching lines @@
     "//testing/scripts/common.py",
     "//testing/xvfb.py",
     "//testing/scripts/run_gtest_perf_test.py",
     "//tools/perf/generate_legacy_perf_dashboard_json.py",
   ]
 
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
   }
 }