[scheduler] Add options to TaskQueue::InsertFence

third_party/WebKit/public/platform/scheduler/base/task_queue.h

Index: third_party/WebKit/public/platform/scheduler/base/task_queue.h
diff --git a/third_party/WebKit/public/platform/scheduler/base/task_queue.h b/third_party/WebKit/public/platform/scheduler/base/task_queue.h
index 4f48b0024cec6e19689cc5c8f130d600a5ff713e..0d5c88e36ad572dca0ef6843b1c7d8211071c898 100644
--- a/third_party/WebKit/public/platform/scheduler/base/task_queue.h
+++ b/third_party/WebKit/public/platform/scheduler/base/task_queue.h
@@ -179,6 +179,12 @@ class BLINK_PLATFORM_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
   // the new fence is hit.
   virtual void InsertFence() = 0;

[alex clarke (OOO till 29th), 2016/11/25 15:06:38]

sorry for the bike shed, but I'm thinking we should make this take an enum:

enum class InsertFencePosition {
  NOW,
  BEGINNING_OF_TIME
};

Where InsertFence(now) does what InsertFence() currently does and
InsertFence(BEGINNING_OF_TIME) does what your propsoed BlockByFence does.  Sami
and I believe this makes the interface easier to understand.

[altimin, 2016/11/25 15:55:27]

Done.

 
+  // Inserts a barrier in the front of the task queue which inhibits all tasks,
+  // effectively disabling this queue. This allows to block task queue for
+  // throttling purposes without interfering with enabling and disabling
+  // task queues for policy reasons.
+  virtual void BlockByFence() = 0;
+
   // Removes any previously added fence and unblocks execution of any tasks
   // blocked by it.
   virtual void RemoveFence() = 0;