Relanding 'Always notify the MediaPlayer of any seek' patch

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 36e03dec0470a582d30d801aaac4e6b1e9333b52..2673c515102f3f7a407d32496fe9e4024e2b7925 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -1995,7 +1995,6 @@ void HTMLMediaElement::seek(double time)
 
     // 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
@@ -2022,30 +2021,17 @@ void HTMLMediaElement::seek(double time)
     // attribute then set the seeking IDL attribute to false and abort these steps.
     RefPtrWillBeRawPtr<TimeRanges> seekableRanges = seekable();
 
-    // 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);
-        }
+    if (!seekableRanges->length()) {
         m_seeking = false;
         return;
     }
     time = seekableRanges->nearest(time, now);
+    if (webMediaPlayer()->seeking() && time == m_lastSeekTime)

[philipj_slow, 2014/12/19 15:06:03]

I don't know, it seems odd that WebMediaPlayer::seeking() is even exposed, the
only other place where it's used also seems like a bit of a workaround at the
wrong layer.

If you tried to explain this in a comment, I think it would become clear that
this depends on WebMediaPlayer-internal details: "If the player is seeking
internally without HTMLMediaElement knowing about it, do nothing and wait for it
to notify us that a seek has completed even though we didn't ask for it"

Was there any trouble in attempting a Chromium-side fix?

+        return;
+
+    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;