message: base_capturer_pipewire: Time the capturer
  This CL records the time it took to capture a frame.
  Cr-Commit-Position: refs/heads/main@{#38933}
diff: #include "modules/portal/xdg_desktop_portal_utils.h"
  #include "rtc_base/checks.h"
  #include "rtc_base/logging.h"
  +#include "rtc_base/time_utils.h"
  +#include "rtc_base/trace_event.h"
  namespace webrtc {
  @@ -136,6 +138,7 @@ void BaseCapturerPipeWire::Start(Callback* callback) {
  }
  void BaseCapturerPipeWire::CaptureFrame() {
  + TRACE_EVENT0("webrtc", "BaseCapturerPipeWire::CaptureFrame");
  if (capturer_failed_) {
  // This could be recoverable if the source list is re-summoned; but for our
  // purposes this is fine, since it requires intervention to resolve and
  @@ -144,6 +147,7 @@ void BaseCapturerPipeWire::CaptureFrame() {
  return;
  }
  + int64_t capture_start_time_nanos = rtc::TimeNanos();
  std::unique_ptr<DesktopFrame> frame =
  options_.screencast_stream()->CaptureFrame();
  @@ -156,6 +160,8 @@ void BaseCapturerPipeWire::CaptureFrame() {
  // the frame, see ScreenCapturerX11::CaptureFrame.
  frame->set_capturer_id(DesktopCapturerId::kWaylandCapturerLinux);
  + frame->set_capture_time_ms((rtc::TimeNanos() - capture_start_time_nanos) /
  + rtc::kNumNanosecsPerMillisec);
  callback_->OnCaptureResult(Result::SUCCESS, std::move(frame));
  }
  