Fix scheduleEvent() crash.

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 8b0714ad486667714457c3238a0a64a5e84ea562..e3039153f0ae2554e84de2cab1d0092c7162703a 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -243,6 +243,7 @@ HTMLMediaElement::HTMLMediaElement(const QualifiedName& tagName, Document* docum
     , m_lastTextTrackUpdateTime(-1)
     , m_textTracks(0)
     , m_ignoreTrackDisplayUpdate(0)
+    , m_inDestructor(false)
 #if ENABLE(WEB_AUDIO)
     , m_audioSourceNode(0)
 #endif
@@ -266,6 +267,8 @@ HTMLMediaElement::HTMLMediaElement(const QualifiedName& tagName, Document* docum
 HTMLMediaElement::~HTMLMediaElement()
 {
     LOG(Media, "HTMLMediaElement::~HTMLMediaElement");
+    m_inDestructor = true;
+
     setShouldDelayLoadEvent(false);
     document()->unregisterForCaptionPreferencesChangedCallbacks(this);
     if (m_textTracks)
@@ -519,6 +522,8 @@ void HTMLMediaElement::scheduleEvent(const AtomicString& eventName)
 #if LOG_MEDIA_EVENTS
     LOG(Media, "HTMLMediaElement::scheduleEvent - scheduling '%s'", eventName.string().ascii().data());
 #endif
+    if (m_inDestructor)
+        return;
     RefPtr<Event> event = Event::create(eventName, false, true);
     event->setTarget(this);