Prepare for per-webview virtual time

components/scheduler/base/task_queue.h

Index: components/scheduler/base/task_queue.h
diff --git a/components/scheduler/base/task_queue.h b/components/scheduler/base/task_queue.h
index c557b7d51da86fa08b46e721a9215e02eb06c26b..b20e0777f08362e92b5e2e733c028d1e12e8ef64 100644
--- a/components/scheduler/base/task_queue.h
+++ b/components/scheduler/base/task_queue.h
@@ -188,6 +188,9 @@ class SCHEDULER_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
   // |domain|.  This is a moderately expensive operation.
   virtual void SetTimeDomain(TimeDomain* domain) = 0;
 
+  // Returns the queue's current TimeDomain.  Can be called from any thread.
+  virtual TimeDomain* GetTimeDomain() const = 0;
+
  protected:
   ~TaskQueue() override {}