Lazily create UserMediaController

This CL addressed guidou's remark on [1], that
was accidentally left off when splitting the CL into
smaller pieces.

[1] https://crrev.com/c/1757490/4/third_party/blink/renderer/modules/modules_initializer.cc#185

BUG=704136
R=guidou@chromium.org, haraken@chromium.org

Change-Id: Ie46cc5eeb9963dc54538d122b0c922a5ec5c4e3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1760407Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Kentaro Hara <haraken@chromium.org>
Auto-Submit: Antonio Gomes <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/master@{#688302}

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

@@ -29,27 +29,33 @@ namespace blink {
 
 const char UserMediaController::kSupplementName[] = "UserMediaController";
 
-UserMediaController::UserMediaController(
-    LocalFrame& frame,
-    std::unique_ptr<UserMediaClient> client)
+UserMediaController::UserMediaController(LocalFrame& frame)
     : Supplement<LocalFrame>(frame),
-      ContextLifecycleObserver(frame.GetDocument()),
-      client_(std::move(client)) {}
+      ContextLifecycleObserver(frame.GetDocument()) {}
 
 void UserMediaController::Trace(blink::Visitor* visitor) {
   Supplement<LocalFrame>::Trace(visitor);
   ContextLifecycleObserver::Trace(visitor);
 }
 
+UserMediaClient* UserMediaController::Client() {
+  if (!client_) {
+    client_ = std::make_unique<UserMediaClient>(
+        GetFrame(), GetFrame()->GetTaskRunner(TaskType::kInternalMedia));
+  }
+
+  return client_.get();
+}
+
 void UserMediaController::ContextDestroyed(ExecutionContext*) {
+  if (!client_)
+    return;
   client_->ContextDestroyed();
 }
 
-void ProvideUserMediaTo(LocalFrame& frame,
-                        std::unique_ptr<UserMediaClient> client) {
+void ProvideUserMediaTo(LocalFrame& frame) {
   UserMediaController::ProvideTo(
-      frame,
-      MakeGarbageCollected<UserMediaController>(frame, std::move(client)));
+      frame, MakeGarbageCollected<UserMediaController>(frame));
 }
 
 }  // namespace blink

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

@@ -46,10 +46,10 @@ class UserMediaController final
  public:
   static const char kSupplementName[];
 
-  UserMediaController(LocalFrame&, std::unique_ptr<UserMediaClient>);
+  UserMediaController(LocalFrame&);
   void Trace(blink::Visitor*) override;
 
-  UserMediaClient* Client() const { return client_.get(); }
+  UserMediaClient* Client();
 
   void RequestUserMedia(UserMediaRequest*);
   void CancelUserMediaRequest(UserMediaRequest*);
@@ -70,30 +70,29 @@ class UserMediaController final
 };
 
 inline void UserMediaController::RequestUserMedia(UserMediaRequest* request) {
-  client_->RequestUserMedia(request);
+  Client()->RequestUserMedia(request);
   has_requested_user_media_ = true;
 }
 
 inline void UserMediaController::CancelUserMediaRequest(
     UserMediaRequest* request) {
-  client_->CancelUserMediaRequest(WebUserMediaRequest(request));
+  Client()->CancelUserMediaRequest(WebUserMediaRequest(request));
 }
 
 inline void UserMediaController::ApplyConstraints(
     ApplyConstraintsRequest* request) {
-  client_->ApplyConstraints(WebApplyConstraintsRequest(request));
+  Client()->ApplyConstraints(WebApplyConstraintsRequest(request));
 }
 
 inline void UserMediaController::StopTrack(MediaStreamComponent* track) {
-  client_->StopTrack(WebMediaStreamTrack(track));
+  Client()->StopTrack(WebMediaStreamTrack(track));
 }
 
 inline bool UserMediaController::HasRequestedUserMedia() {
   return has_requested_user_media_;
 }
 
-MODULES_EXPORT void ProvideUserMediaTo(LocalFrame&,
-                                       std::unique_ptr<UserMediaClient>);
+MODULES_EXPORT void ProvideUserMediaTo(LocalFrame&);
 
 }  // namespace blink
 

third_party/blink/renderer/modules/modules_initializer.cc

@@ -181,9 +181,7 @@ void ModulesInitializer::InstallSupplements(LocalFrame& frame) const {
   DCHECK(client);
   ProvidePushMessagingClientTo(
       frame, MakeGarbageCollected<PushMessagingClient>(frame));
-  ProvideUserMediaTo(
-      frame, std::make_unique<UserMediaClient>(
-                 &frame, frame.GetTaskRunner(TaskType::kInternalMedia)));
+  ProvideUserMediaTo(frame);
   ProvideLocalFileSystemTo(frame, std::make_unique<LocalFileSystemClient>());
 
   ScreenOrientationControllerImpl::ProvideTo(frame);