[Startup Tracing] Remove |is_recording_| in devtool tracing_handler

content/browser/tracing/tracing_controller_impl.cc

Index: content/browser/tracing/tracing_controller_impl.cc
diff --git a/content/browser/tracing/tracing_controller_impl.cc b/content/browser/tracing/tracing_controller_impl.cc
index 28642a4670b3e287328f0525a516e4d998f3fca2..e29425f506b61c7c5170b7ed15d49f6937764d9b 100644
--- a/content/browser/tracing/tracing_controller_impl.cc
+++ b/content/browser/tracing/tracing_controller_impl.cc
@@ -432,6 +432,10 @@ bool TracingControllerImpl::CancelWatchEvent() {
   return true;
 }
 
+bool TracingControllerImpl::IsRecording() const {
+  return is_recording_;
+}
+
 void TracingControllerImpl::AddTraceMessageFilter(
     TraceMessageFilter* trace_message_filter) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {