Prevent more script-observable cases of HTMLMediaElement GC

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 a709141682132ddc3829fd251ecc4500baed28bc..ca1b4f06ccd03b8f77fe2b9a4e4f603d4710818a 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -381,27 +381,14 @@ HTMLMediaElement::~HTMLMediaElement()
 {
     WTF_LOG(Media, "HTMLMediaElement::~HTMLMediaElement(%p)", this);
 
-#if ENABLE(OILPAN)
-    // If the HTMLMediaElement dies with the document we are not
-    // allowed to touch the document to adjust delay load event counts
-    // because the document could have been already
-    // destructed. However, if the HTMLMediaElement dies with the
-    // document there is no need to change the delayed load counts
-    // because no load event will fire anyway. If the document is
-    // still alive we do have to decrement the load delay counts. We
-    // determine if the document is alive via the ActiveDOMObject
-    // which is a context lifecycle observer. If the Document has been
-    // destructed ActiveDOMObject::executionContext() returns 0.
-    if (ActiveDOMObject::executionContext())
-        setShouldDelayLoadEvent(false);
-#else
+    ASSERT(!m_shouldDelayLoadEvent);
+
+#if !ENABLE(OILPAN)
     // HTMLMediaElement and m_asyncEventQueue always become unreachable
     // together. So HTMLMediaElemenet and m_asyncEventQueue are destructed in
     // the same GC. We don't need to close it explicitly in Oilpan.
     m_asyncEventQueue->close();
 
-    setShouldDelayLoadEvent(false);
-
     if (m_textTracks)
         m_textTracks->clearOwner();
     m_audioTracks->shutdown();
@@ -3468,7 +3455,28 @@ void HTMLMediaElement::stop()
 
 bool HTMLMediaElement::hasPendingActivity() const

[scherkus (not reviewing), 2014/09/12 19:05:00]

nice!

 {
-    return (hasAudio() && isPlaying()) || m_asyncEventQueue->hasPendingEvents();
+    if (!document().isActive())
+        return false;
+
+    if (m_shouldDelayLoadEvent)
+        return true;
+
+    if (m_networkState == NETWORK_LOADING)
+        return true;
+
+    if (potentiallyPlaying())
+        return true;
+
+    if (m_seeking)
+        return true;
+
+    if (m_asyncEventQueue->hasPendingEvents())
+        return true;
+
+    if (m_mediaSource)
+        return true;
+
+    return false;
 }
 
 void HTMLMediaElement::contextDestroyed()