Add UserMediaController::HasRequestedUserMedia()

This is intended to make it easier to detect if an RTCPeerConnection is used
together with getUserMedia() or getDisplayMedia() for real-time audio/video.

Bug: 906029
Change-Id: I440fc93567bd9a490047c2bcf3bf5641a4ff3dfa
Reviewed-on: https://chromium-review.googlesource.com/c/1344101Reviewed-by: Henrik Boström <hbos@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609993}

third_party/blink/renderer/modules/mediastream/user_media_controller.h

@@ -53,6 +53,7 @@ class UserMediaController final
   void CancelUserMediaRequest(UserMediaRequest*);
   void ApplyConstraints(ApplyConstraintsRequest*);
   void StopTrack(MediaStreamComponent*);
+  bool HasRequestedUserMedia();
 
   static UserMediaController* From(LocalFrame* frame) {
     return Supplement<LocalFrame>::From<UserMediaController>(frame);
@@ -60,10 +61,12 @@ class UserMediaController final
 
  private:
   std::unique_ptr<UserMediaClient> client_;
+  bool has_requested_user_media_ = false;
 };
 
 inline void UserMediaController::RequestUserMedia(UserMediaRequest* request) {
   client_->RequestUserMedia(request);
+  has_requested_user_media_ = true;
 }
 
 inline void UserMediaController::CancelUserMediaRequest(
@@ -80,6 +83,10 @@ inline void UserMediaController::StopTrack(MediaStreamComponent* track) {
   client_->StopTrack(track);
 }
 
+inline bool UserMediaController::HasRequestedUserMedia() {
+  return has_requested_user_media_;
+}
+
 }  // namespace blink
 
 #endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_MEDIASTREAM_USER_MEDIA_CONTROLLER_H_