[Startup Tracing] Enable startup tracing from config file

components/BUILD.gn

Index: components/BUILD.gn
diff --git a/components/BUILD.gn b/components/BUILD.gn
index aa91a6d074f1d96a9a17d9b096fed82576638fd7..c6ac254687e06305843f0f8f1bfacf5ad0b8a748 100644
--- a/components/BUILD.gn
+++ b/components/BUILD.gn
@@ -98,6 +98,7 @@ group("all_components") {
     "//components/strings",
     "//components/sync_driver",
     "//components/tracing",
+    "//components/tracing:startup_tracing",
     "//components/translate/content/browser",
     "//components/translate/content/common",
     "//components/translate/content/renderer",
@@ -397,9 +398,7 @@ test("components_browsertests") {
   data_deps = [ ":components_tests_pak" ]
 
   if (is_android) {
-    sources += [
-      "test/android/browsertests_apk/components_browser_tests_jni_onload.cc",
-    ]
+    sources += [ "test/android/browsertests_apk/components_browser_tests_jni_onload.cc" ]
     sources -= [ "autofill/content/browser/risk/fingerprint_browsertest.cc" ]
     deps += [ "//testing/android/native_test:native_test_support" ]
     use_launcher = false