Merge 111775

Source/WebCore/html/HTMLMediaElement.cpp

Index: Source/WebCore/html/HTMLMediaElement.cpp
===================================================================
--- Source/WebCore/html/HTMLMediaElement.cpp	(revision 112456)
+++ Source/WebCore/html/HTMLMediaElement.cpp	(working copy)
@@ -714,6 +714,11 @@
 
 void HTMLMediaElement::loadInternal()
 {
+    // Some of the code paths below this function dispatch the BeforeLoad event. This ASSERT helps
+    // us catch those bugs more quickly without needing all the branches to align to actually
+    // trigger the event.
+    ASSERT(!eventDispatchForbidden());
+
     // If we can't start a load right away, start it later.
     Page* page = document()->page();
     if (pageConsentRequiredForLoad() && page && !page->canStartMedia()) {