Revert of Relanding 'Always notify the MediaPlayer of any seek' patch

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 1977 matching lines @@
     // This is needed to avoid getting default playback start position from currentTime().
     double now = m_cachedTime;
 
     // 3 - If the element's seeking IDL attribute is true, then another instance of this algorithm is
     // already running. Abort that other instance of the algorithm without waiting for the step that
     // it is running to complete.
     // Nothing specific to be done here.
 
     // 4 - Set the seeking IDL attribute to true.
     // The flag will be cleared when the engine tells us the time has actually changed.
+    bool previousSeekStillPending = m_seeking;
     m_seeking = true;
 
     // 6 - If the new playback position is later than the end of the media resource, then let it be the end
     // of the media resource instead.
     time = std::min(time, duration());
 
     // 7 - If the new playback position is less than the earliest possible position, let it be that position instead.
     time = std::max(time, 0.0);
 
     // Ask the media engine for the time value in the movie's time scale before comparing with current time. This
     // is necessary because if the seek time is not equal to currentTime but the delta is less than the movie's
     // time scale, we will ask the media engine to "seek" to the current movie time, which may be a noop and
     // not generate a timechanged callback. This means m_seeking will never be cleared and we will never
     // fire a 'seeked' event.
     double mediaTime = webMediaPlayer()->mediaTimeForTimeValue(time);
     if (time != mediaTime) {
         WTF_LOG(Media, "HTMLMediaElement::seek(%p, %f) - media timeline equivalent is %f", this, time, mediaTime);
         time = mediaTime;
     }
 
     // 8 - If the (possibly now changed) new playback position is not in one of the ranges given in the
     // seekable attribute, then let it be the position in one of the ranges given in the seekable attribute
     // that is the nearest to the new playback position. ... If there are no ranges given in the seekable
     // attribute then set the seeking IDL attribute to false and abort these steps.
     RefPtrWillBeRawPtr<TimeRanges> seekableRanges = seekable();
 
-    if (!seekableRanges->length()) {
+    // Short circuit seeking to the current time by just firing the events if no seek is required.
+    // Don't skip calling the media engine if we are in poster mode because a seek should always
+    // cancel poster display.
+    bool noSeekRequired = !seekableRanges->length() || (time == now && displayMode() != Poster);
+
+    if (noSeekRequired) {
+        if (time == now) {
+            scheduleEvent(EventTypeNames::seeking);
+            if (previousSeekStillPending)
+                return;
+            // FIXME: There must be a stable state before timeupdate+seeked are dispatched and seeking
+            // is reset to false. See http://crbug.com/266631
+            scheduleTimeupdateEvent(false);
+            scheduleEvent(EventTypeNames::seeked);
+        }
         m_seeking = false;
         return;
     }
     time = seekableRanges->nearest(time, now);
 
-    if (m_playing && m_lastSeekTime < now)
-        addPlayedRange(m_lastSeekTime, now);
-
+    if (m_playing) {
+        if (m_lastSeekTime < now)
+            addPlayedRange(m_lastSeekTime, now);
+    }
     m_lastSeekTime = time;
     m_sentEndEvent = false;
 
     // 10 - Queue a task to fire a simple event named seeking at the element.
     scheduleEvent(EventTypeNames::seeking);
 
     // 11 - Set the current playback position to the given new playback position.
     webMediaPlayer()->seek(time);
 
     m_initialPlayWithoutUserGestures = false;
@@ skipping 2043 matching lines @@
 
 #if ENABLE(WEB_AUDIO)
 void HTMLMediaElement::clearWeakMembers(Visitor* visitor)
 {
     if (!visitor->isAlive(m_audioSourceNode) && audioSourceProvider())
         audioSourceProvider()->setClient(nullptr);
 }
 #endif
 
 }