Make nesting/running states a RunLoop rather than a MessageLoop concept.

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

Index: third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.cc b/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.cc
index 4265f8f3e199827d85c7c7e6d7d5783944dfc343..a716b11bcc08cdbf506ae51c3eee65aeffd3bf5b 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.cc
@@ -180,7 +180,7 @@ void TaskQueueManager::WakeUpReadyDelayedQueues(LazyNow* lazy_now) {
   }
 }
 
-void TaskQueueManager::OnBeginNestedMessageLoop() {
+void TaskQueueManager::OnBeginNestedRunLoop() {
   // We just entered a nested message loop, make sure there's a DoWork posted or
   // the system will grind to a halt.
   {
@@ -192,7 +192,7 @@ void TaskQueueManager::OnBeginNestedMessageLoop() {
   // When a nested message loop starts, task time observers may want to ignore
   // the current task.
   for (auto& observer : task_time_observers_)
-    observer.OnBeginNestedMessageLoop();
+    observer.OnBeginNestedRunLoop();
 
   delegate_->PostTask(FROM_HERE, immediate_do_work_closure_);
 }