[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..777bc23c63009f7ddb56d577f9c64a157eda0a12 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 +40,35 @@ class BASE_EXPORT TaskAnnotator {
   DISALLOW_COPY_AND_ASSIGN(TaskAnnotator);
 };
 
+class ScopedTaskExecutionEvent {
+ public:
+  ScopedTaskExecutionEvent(const char* file_name, const char* function_name)
+      : function_name_(function_name) {
+    if (trace_event::AllocationContextTracker::capture_enabled()) {

[Sami, 2016/03/17 17:06:26]

Might want to add a throw an UNLIKELY() around this here and below.

+      trace_event::AllocationContextTracker::SetCurrentTaskFileName(file_name);

[Sami, 2016/03/17 17:06:26]

Why isn't the file name also part of the pseudo stack? The fact that we reset it
to null in the destructor might make for some confusing traces when nested tasks
are involved.

+      trace_event::AllocationContextTracker::PushPseudoStackFrame(
+          function_name_);
+    }
+  }
+
+  ~ScopedTaskExecutionEvent() {
+    if (trace_event::AllocationContextTracker::capture_enabled()) {
+      trace_event::AllocationContextTracker::PopPseudoStackFrame(
+          function_name_);
+      trace_event::AllocationContextTracker::SetCurrentTaskFileName(nullptr);
+    }
+  }
+
+ private:
+  const char* 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());
+               (task).posted_from.function_name());        \
+  base::debug::ScopedTaskExecutionEvent scoped_task_event( \
+      (task).posted_from.file_name(), (task).posted_from.function_name());
 
 }  // namespace debug
 }  // namespace base