Fix MediaSource.duration setter behavior to match the current spec.

Source/core/html/HTMLMediaElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1758 matching lines @@
         }
     }
 
     if (m_readyState >= HAVE_METADATA && oldState < HAVE_METADATA) {
         createPlaceholderTracksIfNecessary();
 
         prepareMediaFragmentURI();
 
         selectInitialTracksIfNecessary();
 
+        m_duration = duration();
         scheduleEvent(EventTypeNames::durationchange);
+
         if (isHTMLVideoElement(*this))
             scheduleEvent(EventTypeNames::resize);
         scheduleEvent(EventTypeNames::loadedmetadata);
         if (hasMediaControls())
             mediaControls()->reset();
         if (renderer())
             renderer()->updateFromElement();
     }
 
     bool shouldUpdateDisplayState = false;
@@ skipping 1266 matching lines @@
     }
     else
         m_sentEndEvent = false;
 
     updatePlayState();
 }
 
 void HTMLMediaElement::mediaPlayerDurationChanged()
 {
     WTF_LOG(Media, "HTMLMediaElement::mediaPlayerDurationChanged");
-    durationChanged(duration());
+    // FIXME: Change MediaPlayerClient & WebMediaPlayer to convey
+    // the currentTime when the duration change occured. The current
+    // WebMediaPlayer implementations always clamp currentTime() to
+    // duration() so the requestSeek condition here is always false.
+    durationChanged(duration(), currentTime() > duration());
 }
 
-void HTMLMediaElement::durationChanged(double duration)
+void HTMLMediaElement::durationChanged(double duration, bool requestSeek)
 {
-    WTF_LOG(Media, "HTMLMediaElement::durationChanged(%f)", duration);
+    WTF_LOG(Media, "HTMLMediaElement::durationChanged(%f, %d)", duration, requestSeek);
 
     // Abort if duration unchanged.
     if (m_duration == duration)
         return;
 
+    WTF_LOG(Media, "HTMLMediaElement::durationChanged : %f -> %f", m_duration, duration);
     m_duration = duration;
     scheduleEvent(EventTypeNames::durationchange);
 
     if (hasMediaControls())
         mediaControls()->reset();
     if (renderer())
         renderer()->updateFromElement();
 
-    if (currentTime() > duration)
+    if (requestSeek)
         seek(duration, IGNORE_EXCEPTION);
 }
 
 void HTMLMediaElement::mediaPlayerPlaybackStateChanged()
 {
     WTF_LOG(Media, "HTMLMediaElement::mediaPlayerPlaybackStateChanged");
 
     if (!m_player || m_pausedInternal)
         return;
 
@@ skipping 858 matching lines @@
 
 #if ENABLE(WEB_AUDIO)
 void HTMLMediaElement::clearWeakMembers(Visitor* visitor)
 {
     if (!visitor->isAlive(m_audioSourceNode) && audioSourceProvider())
         audioSourceProvider()->setClient(0);
 }
 #endif
 
 }