Revert of [Startup Tracing] Add --trace-config-file flag

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index f35ed299817fee22c9f6feb56c313f1a7da49ab2..1a5e95048da9d1e392754495be37c32887e0f637 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -28,7 +28,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
-#include "components/tracing/trace_config_file.h"
+#include "components/tracing/startup_tracing.h"
 #include "components/tracing/tracing_switches.h"
 #include "content/browser/browser_main.h"
 #include "content/common/set_process_title.h"
@@ -629,11 +629,9 @@
           base::trace_event::TraceLog::RECORDING_MODE);
     } else if (process_type != switches::kZygoteProcess &&
                process_type != switches::kRendererProcess) {
-      if (tracing::TraceConfigFile::GetInstance()->IsEnabled()) {
-        base::trace_event::TraceLog::GetInstance()->SetEnabled(
-            tracing::TraceConfigFile::GetInstance()->GetTraceConfig(),
-            base::trace_event::TraceLog::RECORDING_MODE);
-      }
+      // There is no need to schedule stopping tracing in this case. Telemetry
+      // will stop tracing on demand later.
+      tracing::EnableStartupTracingIfConfigFileExists();
     }
 
 #if defined(OS_WIN)