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

content/browser/devtools/protocol/tracing_handler.cc

Index: content/browser/devtools/protocol/tracing_handler.cc
diff --git a/content/browser/devtools/protocol/tracing_handler.cc b/content/browser/devtools/protocol/tracing_handler.cc
index 6e9fa55aa48cce3a0f1cd6cb22c0a734675ee6cd..04f18d4b37dbbf121d8af9841d9ff649a0c81fae 100644
--- a/content/browser/devtools/protocol/tracing_handler.cc
+++ b/content/browser/devtools/protocol/tracing_handler.cc
@@ -142,8 +142,10 @@ void TracingHandler::OnRecordingEnabled(
   client_->SendStartResponse(command, StartResponse::Create());
 }
 
-void TracingHandler::OnBufferUsage(float usage) {
-  client_->BufferUsage(BufferUsageParams::Create()->set_value(usage));
+void TracingHandler::OnBufferUsage(float usage, size_t buffer_usage) {
+  client_->BufferUsage(
+      BufferUsageParams::Create()->set_value(usage)->set_event_count(
+          buffer_usage));
 }
 
 void TracingHandler::OnCategoriesReceived(