Tracing: Add metadata indicating whether we have a high-resolution clock available

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 149 matching lines @@
   }
 
   return true;
 }
 
 void TracingControllerImpl::OnEnableRecordingDone(
     const TraceConfig& trace_config,
     const EnableRecordingDoneCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
+  TRACE_EVENT_API_ADD_METADATA_EVENT("IsTimeTicksHighResolution", "value",
+                                     base::TimeTicks::IsHighResolution());
+
   // Notify all child processes.
   for (TraceMessageFilterSet::iterator it = trace_message_filters_.begin();
       it != trace_message_filters_.end(); ++it) {
     it->get()->SendBeginTracing(trace_config);
   }
 
   if (!callback.is_null())
     callback.Run();
 }
 
@@ skipping 757 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