Report trace buffer usage as number of events, not only percentage

content/browser/tracing/tracing_ui.cc

 // Copyright (c) 2012 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_ui.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 112 matching lines @@
       tracing_options,
       base::Bind(&OnRecordingEnabledAck, callback));
 }
 
 void OnRecordingEnabledAck(const WebUIDataSource::GotDataCallback& callback) {
   base::RefCountedString* res = new base::RefCountedString();
   callback.Run(res);
 }
 
 void OnTraceBufferPercentFullResult(
-    const WebUIDataSource::GotDataCallback& callback, float result) {
+    const WebUIDataSource::GotDataCallback& callback,
+    float result,
+    size_t buffer_usage) {
   std::string str = base::DoubleToString(result);
   callback.Run(base::RefCountedString::TakeString(&str));
 }
 
 void OnMonitoringEnabledAck(const WebUIDataSource::GotDataCallback& callback);
 
 bool EnableMonitoring(const std::string& data64,
                       const WebUIDataSource::GotDataCallback& callback) {
   base::debug::TraceOptions tracing_options;
   base::debug::CategoryFilter category_filter("");
@@ skipping 233 matching lines @@
   if (success) {
     web_ui()->CallJavascriptFunction("onUploadComplete",
                                      base::StringValue(report_id));
   } else {
     web_ui()->CallJavascriptFunction("onUploadError",
                                      base::StringValue(error_message));
   }
 }
 
 }  // namespace content