Remove HTMLSourceElement media listener if media attribute is empty

third_party/WebKit/Source/core/html/HTMLSourceElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLSourceElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLSourceElement.cpp b/third_party/WebKit/Source/core/html/HTMLSourceElement.cpp
index f65e834ef53fbc00b5fdca11d4ed3da34a3eb7a1..184cbabc20648081bf075f05cd45bf1901dc6a9d 100644
--- a/third_party/WebKit/Source/core/html/HTMLSourceElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLSourceElement.cpp
@@ -81,10 +81,12 @@ HTMLSourceElement::~HTMLSourceElement()
 
 void HTMLSourceElement::createMediaQueryList(const AtomicString& media)
 {
-    if (media.isEmpty())
+    removeMediaQueryListListener();
+    if (media.isEmpty()) {
+        m_mediaQueryList = nullptr;
         return;
+    }
 
-    removeMediaQueryListListener();
     MediaQuerySet* set = MediaQuerySet::create(media);
     m_mediaQueryList = MediaQueryList::create(&document(), &document().mediaQueryMatcher(), set);
     addMediaQueryListListener();