Record Chrome trace events in tcmalloc heap profiles

base/message_loop.cc

Index: base/message_loop.cc
diff --git a/base/message_loop.cc b/base/message_loop.cc
index 0d8a8ef0d769875f386e244b69932779e9ed2271..3d4cf332b7627e2e7287b680bdba162fb33b11f5 100644
--- a/base/message_loop.cc
+++ b/base/message_loop.cc
@@ -458,9 +458,14 @@ bool MessageLoop::ProcessNextDelayedNonNestableTask() {
 void MessageLoop::RunTask(const PendingTask& pending_task) {
   TRACE_EVENT_FLOW_END0("task", "MessageLoop::PostTask",
       TRACE_ID_MANGLE(GetTaskTraceID(pending_task, this)));
-  TRACE_EVENT2("task", "MessageLoop::RunTask",
-               "src_file", pending_task.posted_from.file_name(),
-               "src_func", pending_task.posted_from.function_name());
+  // RunTask has special memory tracing needs. The file name where the task
+  // was posted is much more useful than "MessageLoop::RunTask" so we invoke
+  // the tracing macros separately with different strings.
+  // TODO(jamescook): Use TRACE_MEMORY2 here when it is implemented.
+  TRACE_MEMORY("task", pending_task.posted_from.file_name());
+  INTERNAL_TRACE_EVENT_ADD_SCOPED("task", "MessageLoop::RunTask",
+      "src_file", pending_task.posted_from.file_name(),
+      "src_func", pending_task.posted_from.function_name());
   DCHECK(nestable_tasks_allowed_);
   // Execute the task and assume the worst: It is probably not reentrant.
   nestable_tasks_allowed_ = false;