[Startup Tracing] Remove |is_recording_| in devtool tracing_handler

content/browser/tracing/tracing_controller_impl.cc

 // Copyright (c) 2013 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.
 #include "content/browser/tracing/tracing_controller_impl.h"
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/json/string_escape.h"
 #include "base/macros.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 414 matching lines @@
 
   for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
       it != trace_message_filters_.end(); ++it) {
     it->get()->SendCancelWatchEvent();
   }
 
   watch_event_callback_.Reset();
   return true;
 }
 
+bool TracingControllerImpl::IsRecording() const {
+  return is_recording_;
+}
+
 void TracingControllerImpl::AddTraceMessageFilter(
     TraceMessageFilter* trace_message_filter) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
         base::Bind(&TracingControllerImpl::AddTraceMessageFilter,
                    base::Unretained(this),
                    make_scoped_refptr(trace_message_filter)));
     return;
   }
 
@@ skipping 410 matching lines @@
   is_monitoring_ = is_monitoring;
 #if !defined(OS_ANDROID)
   for (std::set<TracingUI*>::iterator it = tracing_uis_.begin();
        it != tracing_uis_.end(); it++) {
     (*it)->OnMonitoringStateChanged(is_monitoring);
   }
 #endif
 }
 
 }  // namespace content