Move and rename TaskTimeTracker to public interface exposed to WebThread, use in WebPerf Agent.

third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.h

Index: third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.h
diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.h b/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.h
index 7e84e40b8ce5d69bdb2427ac808e5c71d67ed890..3380270b5a573415241a0c99637cee8974a00f2e 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.h
@@ -18,6 +18,7 @@
 #include "platform/scheduler/base/enqueue_order.h"
 #include "platform/scheduler/base/task_queue_impl.h"
 #include "platform/scheduler/base/task_queue_selector.h"
+#include "public/platform/WebThread.h"
 
 namespace base {
 class TickClock;
@@ -90,6 +91,16 @@ class BLINK_PLATFORM_EXPORT TaskQueueManager
     task_time_tracker_ = task_time_tracker;
   }
 
+  void AddTaskTimeObserver(WebThread::TaskTimeObserver* task_time_observer) {
+    // FIX ME: Make this a list!
+    task_time_observer_ = task_time_observer;
+  }
+
+  void RemoveTaskTimeObserver(WebThread::TaskTimeObserver* task_time_observer) {
+    // FIX ME: Remove from list!
+    task_time_observer_ = nullptr;
+  }
+
   // These functions can only be called on the same thread that the task queue
   // manager executes its tasks on.
   void AddTaskObserver(base::MessageLoop::TaskObserver* task_observer);
@@ -249,6 +260,7 @@ class BLINK_PLATFORM_EXPORT TaskQueueManager
   base::ObserverList<base::MessageLoop::TaskObserver> task_observers_;
 
   TaskTimeTracker* task_time_tracker_;  // NOT OWNED
+  WebThread::TaskTimeObserver* task_time_observer_;  // NOT OWNED

[Sami, 2016/08/19 14:44:56]

Could we define this interface here instead? In principle base/ things shouldn't
depend on core/ things since it creates a cyclic dependency.

Also, it feels like the observer should be on the TaskTimeTracker since I think
we'll also want to use it internally.

[panicker, 2016/08/19 18:06:50]

Could you clarify the base/-core/ issue here? Is public/platform/WebThread.h
considered "core" ?

BTW I first tried to repurpose the TaskTimeTracker interface
(platform/scheduler/base/task_time_tracker.h), but the issue was I couldn't find
a way to hook up the WebPerfAgent to it without making WebThread aware of it.
i.e. in WebPerfAgent if we did something like:
Platform::current()->currentThread()->addTaskTimeTracker(this);
then WebThread needs to be aware of TaskTimeTracker interface.

Instead we can switch the current TaskTimeTracker to merge with the
TaskTimeObserver that I just added (instead of the other way around).
Does that make sense?


 

 
   const char* tracing_category_;
   const char* disabled_by_default_tracing_category_;