fix: use StartUpdating method for PipeWire capturer (#39049)

* fix: use StartUpdating method for PipeWire capturer

Fixed a crash related to PipeWire capturer by adapting to Chromium's
interface changes. Chromium expects a call to
`NativeDesktopMediaList::StartUpdating` with an implementation of
`DesktopMediaListObserver` for delegated capturers like PipeWire. This
interface allows listening to user permission events and listing
sources only after the user has made a choice on the permission dialog.

The interface has been implemented by an inner class to allow listening
to screen and window capture permissions concurrently using two
instances of the class. A patch that was resetting the capturer on the
first refresh has been changed to exclude PipeWire. PipeWire capturer
object will follow the lifecycle of `NativeDesktopMediaList`, as is the
case in Chromium.

Fixes #37463

Co-authored-by: Athul Iddya <[email protected]>

* fix: wait for thumbnails from PipeWire when necessary

The PipeWire stream starts after the dialog is dismissed. If the sources
are listed immediately afterwards, the thumbnail may not have been
generated by that time. Explicitly wait for both thumbnail generation
and a selection on the source dialog before listing sources.

Co-authored-by: Athul Iddya <[email protected]>

---------

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Athul Iddya <[email protected]>

patches/chromium/desktop_media_list.patch

@@ -82,7 +82,7 @@ index 33ca7a53dfb6d2c9e3a33f0065a3acd806e82e01..9fdf2e8ff0056ff407015b914c6b03eb
    const Source& GetSource(int index) const override;
    DesktopMediaList::Type GetMediaListType() const override;
 diff --git a/chrome/browser/media/webrtc/native_desktop_media_list.cc b/chrome/browser/media/webrtc/native_desktop_media_list.cc
-index b548c9fbd3c0bf425447b29dcd866cd27e96b14c..f994ac6086c7b4cd3e8534f34691189d78a21601 100644
+index b548c9fbd3c0bf425447b29dcd866cd27e96b14c..4de719510eaeaaf77cdbd46560f3b4ab1869877a 100644
 --- a/chrome/browser/media/webrtc/native_desktop_media_list.cc
 +++ b/chrome/browser/media/webrtc/native_desktop_media_list.cc
 @@ -147,7 +147,7 @@ BOOL CALLBACK AllHwndCollector(HWND hwnd, LPARAM param) {
@@ -94,17 +94,20 @@ index b548c9fbd3c0bf425447b29dcd866cd27e96b14c..f994ac6086c7b4cd3e8534f34691189d
  #endif
  
  }  // namespace
-@@ -457,6 +457,9 @@ void NativeDesktopMediaList::Worker::RefreshNextThumbnail() {
+@@ -457,6 +457,12 @@ void NativeDesktopMediaList::Worker::RefreshNextThumbnail() {
        FROM_HERE,
        base::BindOnce(&NativeDesktopMediaList::UpdateNativeThumbnailsFinished,
                       media_list_));
 +
 +  // This call is necessary to release underlying OS screen capture mechanisms.
-+  capturer_.reset();
++  // Skip if the source list is delegated, as the source list window will be active.
++  if (!capturer_->GetDelegatedSourceListController()) {
++    capturer_.reset();
++  }
  }
  
  void NativeDesktopMediaList::Worker::OnCaptureResult(
-@@ -829,6 +832,11 @@ void NativeDesktopMediaList::RefreshForVizFrameSinkWindows(
+@@ -829,6 +835,11 @@ void NativeDesktopMediaList::RefreshForVizFrameSinkWindows(
          FROM_HERE, base::BindOnce(&Worker::RefreshThumbnails,
                                    base::Unretained(worker_.get()),
                                    std::move(native_ids), thumbnail_size_));

shell/browser/api/electron_api_desktop_capturer.cc

@@ -181,6 +181,41 @@ DesktopCapturer::DesktopCapturer(v8::Isolate* isolate) {}
 
 DesktopCapturer::~DesktopCapturer() = default;
 
+DesktopCapturer::DesktopListListener::DesktopListListener(
+    OnceCallback update_callback,
+    OnceCallback failure_callback,
+    bool skip_thumbnails)
+    : update_callback_(std::move(update_callback)),
+      failure_callback_(std::move(failure_callback)),
+      have_thumbnail_(skip_thumbnails) {}
+
+DesktopCapturer::DesktopListListener::~DesktopListListener() = default;
+
+void DesktopCapturer::DesktopListListener::OnDelegatedSourceListSelection() {
+  if (have_thumbnail_) {
+    std::move(update_callback_).Run();
+  } else {
+    have_selection_ = true;
+  }
+}
+
+void DesktopCapturer::DesktopListListener::OnSourceThumbnailChanged(int index) {
+  if (have_selection_) {
+    // This is called every time a thumbnail is refreshed. Reset variable to
+    // ensure that the callback is not run again.
+    have_selection_ = false;
+
+    // PipeWire returns a single source, so index is not relevant.
+    std::move(update_callback_).Run();
+  } else {
+    have_thumbnail_ = true;
+  }
+}
+
+void DesktopCapturer::DesktopListListener::OnDelegatedSourceListDismissed() {
+  std::move(failure_callback_).Run();
+}
+
 void DesktopCapturer::StartHandling(bool capture_window,
                                     bool capture_screen,
                                     const gfx::Size& thumbnail_size,
@@ -212,11 +247,22 @@ void DesktopCapturer::StartHandling(bool capture_window,
         window_capturer_ = std::make_unique<NativeDesktopMediaList>(
             DesktopMediaList::Type::kWindow, std::move(capturer));
         window_capturer_->SetThumbnailSize(thumbnail_size);
-        window_capturer_->Update(
-            base::BindOnce(&DesktopCapturer::UpdateSourcesList,
-                           weak_ptr_factory_.GetWeakPtr(),
-                           window_capturer_.get()),
-            /* refresh_thumbnails = */ true);
+
+        OnceCallback update_callback = base::BindOnce(
+            &DesktopCapturer::UpdateSourcesList, weak_ptr_factory_.GetWeakPtr(),
+            window_capturer_.get());
+
+        if (window_capturer_->IsSourceListDelegated()) {
+          OnceCallback failure_callback = base::BindOnce(
+              &DesktopCapturer::HandleFailure, weak_ptr_factory_.GetWeakPtr());
+          window_listener_ = std::make_unique<DesktopListListener>(
+              std::move(update_callback), std::move(failure_callback),
+              thumbnail_size.IsEmpty());
+          window_capturer_->StartUpdating(window_listener_.get());
+        } else {
+          window_capturer_->Update(std::move(update_callback),
+                                   /* refresh_thumbnails = */ true);
+        }
       }
     }
 
@@ -226,11 +272,22 @@ void DesktopCapturer::StartHandling(bool capture_window,
         screen_capturer_ = std::make_unique<NativeDesktopMediaList>(
             DesktopMediaList::Type::kScreen, std::move(capturer));
         screen_capturer_->SetThumbnailSize(thumbnail_size);
-        screen_capturer_->Update(
-            base::BindOnce(&DesktopCapturer::UpdateSourcesList,
-                           weak_ptr_factory_.GetWeakPtr(),
-                           screen_capturer_.get()),
-            /* refresh_thumbnails = */ true);
+
+        OnceCallback update_callback = base::BindOnce(
+            &DesktopCapturer::UpdateSourcesList, weak_ptr_factory_.GetWeakPtr(),
+            screen_capturer_.get());
+
+        if (screen_capturer_->IsSourceListDelegated()) {
+          OnceCallback failure_callback = base::BindOnce(
+              &DesktopCapturer::HandleFailure, weak_ptr_factory_.GetWeakPtr());
+          screen_listener_ = std::make_unique<DesktopListListener>(
+              std::move(update_callback), std::move(failure_callback),
+              thumbnail_size.IsEmpty());
+          screen_capturer_->StartUpdating(screen_listener_.get());
+        } else {
+          screen_capturer_->Update(std::move(update_callback),
+                                   /* refresh_thumbnails = */ true);
+        }
       }
     }
   }
@@ -269,12 +326,7 @@ void DesktopCapturer::UpdateSourcesList(DesktopMediaList* list) {
       // |media_list_sources|.
       if (!webrtc::DxgiDuplicatorController::Instance()->GetDeviceNames(
               &device_names)) {
-        v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
-        v8::HandleScope scope(isolate);
-        gin_helper::CallMethod(this, "_onerror", "Failed to get sources.");
-
-        Unpin();
-
+        HandleFailure();
         return;
       }
 
@@ -324,6 +376,14 @@ void DesktopCapturer::UpdateSourcesList(DesktopMediaList* list) {
   }
 }
 
+void DesktopCapturer::HandleFailure() {
+  v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
+  v8::HandleScope scope(isolate);
+  gin_helper::CallMethod(this, "_onerror", "Failed to get sources.");
+
+  Unpin();
+}
+
 // static
 gin::Handle<DesktopCapturer> DesktopCapturer::Create(v8::Isolate* isolate) {
   auto handle = gin::CreateHandle(isolate, new DesktopCapturer(isolate));

shell/browser/api/electron_api_desktop_capturer.h

@@ -62,8 +62,37 @@ class DesktopCapturer : public gin::Wrappable<DesktopCapturer>,
   void OnDelegatedSourceListDismissed() override {}
 
  private:
+  using OnceCallback = base::OnceClosure;
+
+  class DesktopListListener : public DesktopMediaListObserver {
+   public:
+    DesktopListListener(OnceCallback update_callback,
+                        OnceCallback failure_callback,
+                        bool skip_thumbnails);
+    ~DesktopListListener() override;
+
+   protected:
+    void OnSourceAdded(int index) override {}
+    void OnSourceRemoved(int index) override {}
+    void OnSourceMoved(int old_index, int new_index) override {}
+    void OnSourceNameChanged(int index) override {}
+    void OnSourceThumbnailChanged(int index) override;
+    void OnSourcePreviewChanged(size_t index) override {}
+    void OnDelegatedSourceListSelection() override;
+    void OnDelegatedSourceListDismissed() override;
+
+   private:
+    OnceCallback update_callback_;
+    OnceCallback failure_callback_;
+    bool have_selection_ = false;
+    bool have_thumbnail_ = false;
+  };
+
   void UpdateSourcesList(DesktopMediaList* list);
+  void HandleFailure();
 
+  std::unique_ptr<DesktopListListener> window_listener_;
+  std::unique_ptr<DesktopListListener> screen_listener_;
   std::unique_ptr<DesktopMediaList> window_capturer_;
   std::unique_ptr<DesktopMediaList> screen_capturer_;
   std::vector<DesktopCapturer::Source> captured_sources_;