## Adds a flag to prevent autoplaying media

--- a/chrome/browser/ungoogled_flag_entries.h
+++ b/chrome/browser/ungoogled_flag_entries.h
@@ -7,1 +7,5 @@
+    {"prevent-autoplay",
+     "PreventAutoplay",
+     "Prevents media from playing automatically.  ungoogled-chromium flag.",
+     kOsAll, FEATURE_VALUE_TYPE(media::kPreventAutoplay)},
 #endif  // CHROME_BROWSER_UNGOOGLED_FLAG_ENTRIES_H_
--- a/media/base/media_switches.cc
+++ b/media/base/media_switches.cc
@@ -908,6 +908,8 @@ const base::Feature kBresenhamCadence{"B
 const base::Feature kPlaybackSpeedButton{"PlaybackSpeedButton",
                                          base::FEATURE_ENABLED_BY_DEFAULT};
 
+const base::Feature kPreventAutoplay{"PreventAutoplay", base::FEATURE_DISABLED_BY_DEFAULT};
+
 bool IsVideoCaptureAcceleratedJpegDecodingEnabled() {
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableAcceleratedMjpegDecode)) {
--- a/media/base/media_switches.h
+++ b/media/base/media_switches.h
@@ -255,6 +255,8 @@ MEDIA_EXPORT extern const base::Feature
 MEDIA_EXPORT extern const base::Feature kDeprecateLowUsageCodecs;
 #endif
 
+MEDIA_EXPORT extern const base::Feature kPreventAutoplay;
+
 // Based on a |command_line| and the current platform, returns the effective
 // autoplay policy. In other words, it will take into account the default policy
 // if none is specified via the command line and options passed for testing.
--- a/third_party/blink/renderer/core/dom/document.cc
+++ b/third_party/blink/renderer/core/dom/document.cc
@@ -4081,6 +4081,7 @@ void Document::SetURL(const KURL& url) {
   if (GetFrame()) {
     if (FrameScheduler* frame_scheduler = GetFrame()->GetFrameScheduler())
       frame_scheduler->TraceUrlChange(url_.GetString());
+    GetFrame()->ClearRealUserActivation();
   }
 }
 
--- a/third_party/blink/renderer/core/frame/local_frame.h
+++ b/third_party/blink/renderer/core/frame/local_frame.h
@@ -722,7 +722,17 @@ class CORE_EXPORT LocalFrame final : pub
   void RebindTextInputHostForTesting();
 #endif
 
+  void RealUserActivation() { rua_time_ = base::TimeTicks::Now(); }
+  void ClearRealUserActivation() { rua_time_ = base::TimeTicks(); rua_allowed_ = false; }
+  bool HasRealUserActivation() {
+    if (!rua_allowed_) rua_allowed_ = (base::TimeTicks::Now() - rua_time_).InSeconds() < 1;
+    return rua_allowed_;
+  }
+
  private:
+  bool rua_allowed_ = false;
+  base::TimeTicks rua_time_ = base::TimeTicks();
+
   friend class FrameNavigationDisabler;
   // LocalFrameMojoHandler is a part of LocalFrame.
   friend class LocalFrameMojoHandler;
--- a/third_party/blink/renderer/core/html/media/html_media_element.cc
+++ b/third_party/blink/renderer/core/html/media/html_media_element.cc
@@ -2530,6 +2530,7 @@ bool HTMLMediaElement::ended() const {
 }
 
 bool HTMLMediaElement::Autoplay() const {
+  if (base::FeatureList::IsEnabled(media::kPreventAutoplay)) return false;
   return FastHasAttribute(html_names::kAutoplayAttr);
 }
 
@@ -2638,6 +2639,17 @@ ScriptPromise HTMLMediaElement::playForB
 absl::optional<DOMExceptionCode> HTMLMediaElement::Play() {
   DVLOG(2) << "play(" << *this << ")";
 
+  if (base::FeatureList::IsEnabled(media::kPreventAutoplay)) {
+    if (!GetDocument().GetFrame()->HasRealUserActivation()) {
+      if (rua_mute_state_ == -1) rua_mute_state_ = muted_;
+      return DOMExceptionCode::kNotAllowedError;
+    }
+    if (rua_mute_state_ > -1) {
+      if (muted_ != rua_mute_state_) setMuted(rua_mute_state_);
+      rua_mute_state_ = -1;
+    }
+  }
+
   absl::optional<DOMExceptionCode> exception_code =
       autoplay_policy_->RequestPlay();
 
--- a/third_party/blink/renderer/core/html/media/html_media_element.h
+++ b/third_party/blink/renderer/core/html/media/html_media_element.h
@@ -763,6 +763,8 @@ class CORE_EXPORT HTMLMediaElement
   // playback raters other than 1.0.
   bool preserves_pitch_ = true;
 
+  signed char rua_mute_state_ = -1;
+
   // Keeps track of when the player seek event was sent to the browser process.
   base::TimeTicks last_seek_update_time_;
 
--- a/third_party/blink/renderer/core/input/event_handler.cc
+++ b/third_party/blink/renderer/core/input/event_handler.cc
@@ -830,6 +830,7 @@ WebInputEventResult EventHandler::Handle
     return WebInputEventResult::kHandledSuppressed;
   }
 
+  frame_->RealUserActivation();
   LocalFrame::NotifyUserActivation(
       frame_, mojom::blink::UserActivationNotificationType::kInteraction,
       RuntimeEnabledFeatures::BrowserVerifiedUserActivationMouseEnabled());
--- a/third_party/blink/renderer/core/input/gesture_manager.cc
+++ b/third_party/blink/renderer/core/input/gesture_manager.cc
@@ -240,6 +240,7 @@ WebInputEventResult GestureManager::Hand
       FlooredIntPoint(gesture_event.PositionInRootFrame());
   Node* tapped_node = current_hit_test.InnerNode();
   Element* tapped_element = current_hit_test.InnerElement();
+  if(tapped_node) tapped_node->GetDocument().GetFrame()->RealUserActivation();
   LocalFrame::NotifyUserActivation(
       tapped_node ? tapped_node->GetDocument().GetFrame() : nullptr,
       mojom::blink::UserActivationNotificationType::kInteraction);
@@ -403,6 +404,7 @@ WebInputEventResult GestureManager::Hand
     return WebInputEventResult::kNotHandled;
   }
 
+  if(inner_node) inner_node->GetDocument().GetFrame()->RealUserActivation();
   LocalFrame::NotifyUserActivation(
       inner_node ? inner_node->GetDocument().GetFrame() : nullptr,
       mojom::blink::UserActivationNotificationType::kInteraction);
--- a/third_party/blink/renderer/core/input/keyboard_event_manager.cc
+++ b/third_party/blink/renderer/core/input/keyboard_event_manager.cc
@@ -210,6 +210,7 @@ WebInputEventResult KeyboardEventManager
   if (!is_modifier && initial_key_event.dom_key != ui::DomKey::ESCAPE &&
       (initial_key_event.GetType() == WebInputEvent::Type::kKeyDown ||
        initial_key_event.GetType() == WebInputEvent::Type::kRawKeyDown)) {
+    frame_->RealUserActivation();
     LocalFrame::NotifyUserActivation(
         frame_, mojom::blink::UserActivationNotificationType::kInteraction,
         RuntimeEnabledFeatures::BrowserVerifiedUserActivationKeyboardEnabled());
--- a/third_party/blink/renderer/core/input/pointer_event_manager.cc
+++ b/third_party/blink/renderer/core/input/pointer_event_manager.cc
@@ -650,6 +650,7 @@ WebInputEventResult PointerEventManager:
   // associated with so just pick the pointer event that comes.
   if (event.GetType() == WebInputEvent::Type::kPointerUp &&
       !non_hovering_pointers_canceled_ && pointer_event_target.target_frame) {
+    pointer_event_target.target_frame->RealUserActivation();
     LocalFrame::NotifyUserActivation(
         pointer_event_target.target_frame,
         mojom::blink::UserActivationNotificationType::kInteraction);
--- a/third_party/blink/renderer/modules/mediasession/media_session.cc
+++ b/third_party/blink/renderer/modules/mediasession/media_session.cc
@@ -410,6 +410,7 @@ void MediaSession::DidReceiveAction(
   LocalDOMWindow* window = GetSupplementable()->DomWindow();
   if (!window)
     return;
+  window->GetFrame()->RealUserActivation();
   LocalFrame::NotifyUserActivation(
       window->GetFrame(),
       mojom::blink::UserActivationNotificationType::kInteraction);