scheduler: Maintain a constant enqueue order for every task

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

Index: third_party/WebKit/Source/platform/scheduler/base/work_queue.h
diff --git a/third_party/WebKit/Source/platform/scheduler/base/work_queue.h b/third_party/WebKit/Source/platform/scheduler/base/work_queue.h
index 1dd47e12f6f6856158e43f6c698efe1622c39a49..5d139d0cbae92f320cf8c7bbabc152fcd7a00f62 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/work_queue.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/work_queue.h
@@ -98,11 +98,11 @@ class BLINK_PLATFORM_EXPORT WorkQueue {
   bool ShouldRunBefore(const WorkQueue* other_queue) const;
 
   // Submit a fence. When TakeTaskFromWorkQueue encounters a task whose
-  // enqueue_order is >= |fence| then the WorkQueue will start pretending to be.
-  // empty.
+  // sequence number is >= |fence| then the WorkQueue will start pretending to
+  // be. empty.
   // Inserting a fence may supersede a previous one and unblock some tasks.
   // Returns true if any tasks where unblocked, returns false otherwise.
-  bool InsertFence(EnqueueOrder fence);
+  bool InsertFence(SequenceNumber fence);
 
   // Removes any fences that where added and if WorkQueue was pretending to be
   // empty, then the real value is reported to WorkQueueSets. Returns true if
@@ -121,7 +121,7 @@ class BLINK_PLATFORM_EXPORT WorkQueue {
   size_t work_queue_set_index_;
   HeapHandle heap_handle_;
   const char* const name_;
-  EnqueueOrder fence_;
+  SequenceNumber fence_;
   const QueueType queue_type_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkQueue);