Count how often a Media Fragments URI is applied in HTMLMediaElement

Source/core/html/HTMLMediaElement.cpp

Index: Source/core/html/HTMLMediaElement.cpp
diff --git a/Source/core/html/HTMLMediaElement.cpp b/Source/core/html/HTMLMediaElement.cpp
index 932490ee927c791ab54c9c3538ea2b5a0378531d..c4e4d53ac87b8ea6ce37b255c4d6c9ae0d9efeb0 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -2441,6 +2441,7 @@ void HTMLMediaElement::playbackProgressTimerFired(Timer<HTMLMediaElement>*)
     if (m_fragmentEndTime != MediaPlayer::invalidTime() && currentTime() >= m_fragmentEndTime && m_playbackRate > 0) {
         m_fragmentEndTime = MediaPlayer::invalidTime();
         if (!m_mediaController && !m_paused) {
+            UseCounter::count(document(), UseCounter::HTMLMediaElementPauseAtFragmentEnd);
             // changes paused to true and fires a simple event named pause at the media element.
             pause();
         }
@@ -3884,6 +3885,7 @@ void HTMLMediaElement::applyMediaFragmentURI()
 {
     if (m_fragmentStartTime != MediaPlayer::invalidTime()) {
         m_sentEndEvent = false;
+        UseCounter::count(document(), UseCounter::HTMLMediaElementSeekToFragmentStart);
         seek(m_fragmentStartTime, IGNORE_EXCEPTION);
     }
 }