Delete rtc::TaskQueue::Current in favor of webrtc::TaskQueueBase::Current

Bug: webrtc:10191
Change-Id: I506cc50a90c73a6a4f6a3de36de0999cca72f5ba
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/126230
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27035}
diff --git a/rtc_base/task_queue.cc b/rtc_base/task_queue.cc
index ed489eb..d11b34e 100644
--- a/rtc_base/task_queue.cc
+++ b/rtc_base/task_queue.cc
@@ -16,9 +16,7 @@
 
 TaskQueue::TaskQueue(
     std::unique_ptr<webrtc::TaskQueueBase, webrtc::TaskQueueDeleter> task_queue)
-    : impl_(task_queue.release()) {
-  impl_->task_queue_ = this;
-}
+    : impl_(task_queue.release()) {}
 
 TaskQueue::TaskQueue(const char* queue_name, Priority priority)
     : TaskQueue(webrtc::GlobalTaskQueueFactory().CreateTaskQueue(queue_name,
@@ -32,17 +30,8 @@
   impl_->Delete();
 }
 
-// static
-TaskQueue* TaskQueue::Current() {
-  webrtc::TaskQueueBase* impl = webrtc::TaskQueueBase::Current();
-  if (impl == nullptr) {
-    return nullptr;
-  }
-  return impl->task_queue_;
-}
-
 bool TaskQueue::IsCurrent() const {
-  return Current() == this;
+  return impl_->IsCurrent();
 }
 
 void TaskQueue::PostTask(std::unique_ptr<QueuedTask> task) {