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

content/browser/tracing/tracing_ui.cc

Index: content/browser/tracing/tracing_ui.cc
diff --git a/content/browser/tracing/tracing_ui.cc b/content/browser/tracing/tracing_ui.cc
index 95e3ab92cdec6ce18a5c966dbbcfad86ce97e4e6..6d16015b688897504de5de1429f70c2a173fbb67 100644
--- a/content/browser/tracing/tracing_ui.cc
+++ b/content/browser/tracing/tracing_ui.cc
@@ -130,7 +130,9 @@ void OnRecordingEnabledAck(const WebUIDataSource::GotDataCallback& callback) {
 }
 
 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));
 }