[tracing] Adding task information to heap profiler

base/debug/task_annotator.h

Index: base/debug/task_annotator.h
diff --git a/base/debug/task_annotator.h b/base/debug/task_annotator.h
index 443c71bf30169ded3042c90d07343710b4cdab42..5bbce8b11c191aeb5b5bb737207cc4f6c036f21b 100644
--- a/base/debug/task_annotator.h
+++ b/base/debug/task_annotator.h
@@ -9,6 +9,7 @@
 
 #include "base/base_export.h"
 #include "base/macros.h"
+#include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 
 namespace base {
 struct PendingTask;
@@ -39,10 +40,12 @@ class BASE_EXPORT TaskAnnotator {
   DISALLOW_COPY_AND_ASSIGN(TaskAnnotator);
 };
 
-#define TRACE_TASK_EXECUTION(run_function, task)           \
-  TRACE_EVENT2("toplevel", (run_function), "src_file",     \
-               (task).posted_from.file_name(), "src_func", \
-               (task).posted_from.function_name());
+#define TRACE_TASK_EXECUTION(run_function, task)                               \
+  TRACE_EVENT2("toplevel", (run_function), "src_file",                         \
+               (task).posted_from.file_name(), "src_func",                     \
+               (task).posted_from.function_name());                            \
+  base::trace_event::AllocationContextTracker::ScopedTaskExecutionEvent event( \

[Primiano Tucci (use gerrit), 2016/03/25 01:56:31]

I'd use a name which tries to avoid conflics.
Also, to be honest I think that either:
- this entire macro should really be inside trace_event.h. There you could use
INTERNAL_TRACE_EVENT_UID to mangle the name for the event variable.
or
- ScopedTaskExecutionEvent should be a class inside task_annotator.h, and make
the push methods public in the tracker

[ssid, 2016/03/28 18:14:49]

yes I think its a good idea to move it to trace_event.h. Lets see what others
think about this.

If I add it here, I would have to explain about why task execution is special
case what is heap profiler and stuff to the base/debug owners, it is easier to
explain to trace_event/ folks.

+      (task).posted_from.file_name(), (task).posted_from.function_name());

[Primiano Tucci (use gerrit), 2016/03/25 01:56:31]

Looks like you never use the second argument. Why bothering passing that?

[ssid, 2016/03/28 18:14:49]

I was hoping I will need it soon and I will have to change this file again,
asking other people. Now its inside trace_event/ can change later when needed.

 
 }  // namespace debug
 }  // namespace base