1 files changed, 30 insertions, 7 deletions
diff --git a/chromium/content/browser/media/capture/io_surface_capture_device_base_mac.cc b/chromium/content/browser/media/capture/io_surface_capture_device_base_mac.cc
index 36df6dfd987..ec490d38ff6 100644
--- a/chromium/content/browser/media/capture/io_surface_capture_device_base_mac.cc
+++ b/chromium/content/browser/media/capture/io_surface_capture_device_base_mac.cc
@@ -9,6 +9,23 @@
 
 namespace content {
 
+namespace {
+
+float ComputeMinFrameRate(float requested_frame_rate) {
+  // Set a minimum frame rate of 5 fps, unless the requested frame rate is
+  // even lower.
+  constexpr float kMinFrameRate = 5.f;
+
+  // Don't send frames at more than 80% the requested rate, because doing so
+  // can stochastically toggle between repeated and new frames.
+  constexpr float kRequestedFrameRateFactor = 0.8f;
+
+  return std::min(requested_frame_rate * kRequestedFrameRateFactor,
+                  kMinFrameRate);
+}
+
+}  // namespace
+
 IOSurfaceCaptureDeviceBase::IOSurfaceCaptureDeviceBase() = default;
 IOSurfaceCaptureDeviceBase::~IOSurfaceCaptureDeviceBase() = default;
 
@@ -19,24 +36,20 @@ void IOSurfaceCaptureDeviceBase::AllocateAndStart(
   DCHECK(client && !client_);
   client_ = std::move(client);
   capture_params_ = params;
+  min_frame_rate_ =
+      ComputeMinFrameRate(capture_params_.requested_format.frame_rate);
 
   OnStart();
 }
 
 void IOSurfaceCaptureDeviceBase::StopAndDeAllocate() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  min_frame_rate_enforcement_timer_.reset();
   weak_factory_base_.InvalidateWeakPtrs();
 
   OnStop();
 }
 
-void IOSurfaceCaptureDeviceBase::RequestRefreshFrame() {
-  // Simply send the last received surface, if we ever received one.
-  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
-  if (last_received_io_surface_)
-    SendLastReceivedIOSurfaceToClient();
-}
-
 void IOSurfaceCaptureDeviceBase::OnReceivedIOSurfaceFromStream(
     gfx::ScopedInUseIOSurface io_surface,
     const media::VideoCaptureFormat& capture_format) {
@@ -67,6 +80,16 @@ void IOSurfaceCaptureDeviceBase::SendLastReceivedIOSurfaceToClient() {
                                          last_received_capture_format_,
                                          gfx::ColorSpace::CreateREC709()),
       {}, now, now - first_frame_time_);
+
+  // Reset `min_frame_rate_enforcement_timer_`.
+  if (!min_frame_rate_enforcement_timer_) {
+    min_frame_rate_enforcement_timer_ = std::make_unique<base::RepeatingTimer>(
+        FROM_HERE, base::Seconds(1 / min_frame_rate_),
+        base::BindRepeating(
+            &IOSurfaceCaptureDeviceBase::SendLastReceivedIOSurfaceToClient,
+            weak_factory_base_.GetWeakPtr()));
+  }
+  min_frame_rate_enforcement_timer_->Reset();
 }
 
 void IOSurfaceCaptureDeviceBase::ComputeFrameSizeAndDestRect(