[scheduler] Add options to TaskQueue::InsertFence

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_H_
 #define THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_H_
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/optional.h"
@@ skipping 159 matching lines @@
   virtual void SetTimeDomain(TimeDomain* domain) = 0;
 
   // Returns the queue's current TimeDomain.  Can be called from any thread.
   virtual TimeDomain* GetTimeDomain() const = 0;
 
   // Inserts a barrier into the task queue which inhibits non-delayed tasks
   // posted after this point, or delayed tasks which are not yet ready to run,
   // from being executed until the fence is cleared.  If a fence already existed
   // the one supersedes it and previously blocked tasks will now run up until
   // 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;
 
   virtual bool BlockedByFence() const = 0;
 
  protected:
   ~TaskQueue() override {}
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueue);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_H_