Implement frame attribution (FrameBlamer)

components/scheduler/base/task_queue.h

Index: components/scheduler/base/task_queue.h
diff --git a/components/scheduler/base/task_queue.h b/components/scheduler/base/task_queue.h
index b20e0777f08362e92b5e2e733c028d1e12e8ef64..4f96aab434b1d45251c1968c8c2369094645de15 100644
--- a/components/scheduler/base/task_queue.h
+++ b/components/scheduler/base/task_queue.h
@@ -8,8 +8,15 @@
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
+#include "base/trace_event/trace_event.h"
 #include "components/scheduler/scheduler_export.h"
 
+namespace base {
+namespace trace_event {
+class BlameContext;
+}
+}
+
 namespace scheduler {
 class TimeDomain;
 
@@ -184,6 +191,11 @@ class SCHEDULER_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
   virtual void RemoveTaskObserver(
       base::MessageLoop::TaskObserver* task_observer) = 0;
 
+  // Set the blame context which is entered and left while executing tasks from
+  // this task queue. |blame_context| must be null or outlive this task queue.

[alex clarke (OOO till 29th), 2016/03/21 14:38:36]

Please mention this is main thread only.

[Sami, 2016/03/21 15:18:05]

Done.

+  virtual void SetBlameContext(
+      base::trace_event::BlameContext* blame_context) = 0;
+
   // Removes the task queue from the previous TimeDomain and adds it to
   // |domain|.  This is a moderately expensive operation.
   virtual void SetTimeDomain(TimeDomain* domain) = 0;