Android: Make netlog available in startup traces.

net/log/trace_net_log_observer.cc

 // 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.
 
 #include "net/log/trace_net_log_observer.h"
 
 #include <stdio.h>
 
 #include <memory>
 #include <string>
@@ skipping 72 matching lines @@
           std::unique_ptr<base::trace_event::ConvertableToTraceFormat>(
               new TracedValue(std::move(params))));
       break;
   }
 }
 
 void TraceNetLogObserver::WatchForTraceStart(NetLog* netlog) {
   DCHECK(!net_log_to_watch_);
   DCHECK(!net_log());
   net_log_to_watch_ = netlog;
+  // Tracing can start before the observer is even created, for instance for
+  // startup tracing.
+  if (base::trace_event::TraceLog::GetInstance()->IsEnabled())
+    OnTraceLogEnabled();
   base::trace_event::TraceLog::GetInstance()->AddEnabledStateObserver(this);
 }
 
 void TraceNetLogObserver::StopWatchForTraceStart() {
   // Should only stop if is currently watching.
   DCHECK(net_log_to_watch_);
   base::trace_event::TraceLog::GetInstance()->RemoveEnabledStateObserver(this);
   if (net_log())
     net_log()->DeprecatedRemoveObserver(this);
   net_log_to_watch_ = NULL;
 }
 
 void TraceNetLogObserver::OnTraceLogEnabled() {
   net_log_to_watch_->DeprecatedAddObserver(this, NetLogCaptureMode::Default());
 }
 
 void TraceNetLogObserver::OnTraceLogDisabled() {
   if (net_log())
     net_log()->DeprecatedRemoveObserver(this);
 }
 
 }  // namespace net