Implement support for Chrome task origin tracing. #4/4

This CL forwards BlockingCall client locations to
BlockingCallImpl.

Fixed: chromium:1416199
Change-Id: Ic5865280ec5c72a09a64419940b8343e8a54986b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/295624
Commit-Queue: Markus Handell <handellm@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39442}

rtc_base/thread.h

@@ -309,18 +309,20 @@ class RTC_LOCKABLE RTC_EXPORT Thread : public webrtc::TaskQueueBase {
   // See ScopedDisallowBlockingCalls for details.
   // NOTE: Blocking calls are DISCOURAGED, consider if what you're doing can
   // be achieved with PostTask() and callbacks instead.
-  // TODO(crbug.com/1416199): Remove virtual and pass location of the caller
-  // once subclasses migrated.
-  virtual void BlockingCall(FunctionView<void()> functor) {
-    BlockingCallImpl(std::move(functor), webrtc::Location::Current());
+  void BlockingCall(
+      FunctionView<void()> functor,
+      const webrtc::Location& location = webrtc::Location::Current()) {
+    BlockingCallImpl(std::move(functor), location);
   }
 
   template <typename Functor,
             typename ReturnT = std::invoke_result_t<Functor>,
             typename = typename std::enable_if_t<!std::is_void_v<ReturnT>>>
-  ReturnT BlockingCall(Functor&& functor) {
+  ReturnT BlockingCall(
+      Functor&& functor,
+      const webrtc::Location& location = webrtc::Location::Current()) {
     ReturnT result;
-    BlockingCall([&] { result = std::forward<Functor>(functor)(); });
+    BlockingCall([&] { result = std::forward<Functor>(functor)(); }, location);
     return result;
   }
 

test/time_controller/simulated_thread.cc

@@ -61,7 +61,8 @@ void SimulatedThread::RunReady(Timestamp at_time) {
   }
 }
 
-void SimulatedThread::BlockingCall(rtc::FunctionView<void()> functor) {
+void SimulatedThread::BlockingCallImpl(rtc::FunctionView<void()> functor,
+                                       const Location& /*location*/) {
   if (IsQuitting())
     return;
 

test/time_controller/simulated_thread.h

@@ -36,7 +36,8 @@ class SimulatedThread : public rtc::Thread,
   TaskQueueBase* GetAsTaskQueue() override { return this; }
 
   // Thread interface
-  void BlockingCall(rtc::FunctionView<void()> functor) override;
+  void BlockingCallImpl(rtc::FunctionView<void()> functor,
+                        const Location& location) override;
   void PostTaskImpl(absl::AnyInvocable<void() &&> task,
                     const PostTaskTraits& traits,
                     const Location& location) override;