Consistently use ElementTraversal API when looking for an Element

Source/core/html/HTMLMediaElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 446 matching lines @@
         HTMLElement::parseAttribute(name, value);
 }
 
 void HTMLMediaElement::finishParsingChildren()
 {
     HTMLElement::finishParsingChildren();
 
     if (!RuntimeEnabledFeatures::videoTrackEnabled())
         return;
 
-    for (Node* node = firstChild(); node; node = node->nextSibling()) {
-        if (node->hasTagName(trackTag)) {
+    for (Element* child = ElementTraversal::firstWithin(*this); child; child = ElementTraversal::nextSibling(*child)) {
+        if (child->hasTagName(trackTag)) {
             scheduleDelayedAction(LoadTextTrackResource);
             break;
         }
     }
 }
 
 bool HTMLMediaElement::rendererIsNeeded(const RenderStyle& style)
 {
     return controls() ? HTMLElement::rendererIsNeeded(style) : false;
 }
@@ skipping 254 matching lines @@
 
 void HTMLMediaElement::selectMediaResource()
 {
     WTF_LOG(Media, "HTMLMediaElement::selectMediaResource");
 
     enum Mode { attribute, children };
 
     // 3 - If the media element has a src attribute, then let mode be attribute.
     Mode mode = attribute;
     if (!fastHasAttribute(srcAttr)) {
-        Node* node;
-        for (node = firstChild(); node; node = node->nextSibling()) {
-            if (node->hasTagName(sourceTag))
+        Element* element;
+        for (element = ElementTraversal::firstWithin(*this); element; element = ElementTraversal::nextSibling(*element)) {
+            if (element->hasTagName(sourceTag))
                 break;
         }
 
         // Otherwise, if the media element does not have a src attribute but has a source
         // element child, then let mode be children and let candidate be the first such
         // source element child in tree order.
-        if (node) {
+        if (element) {
             mode = children;
-            m_nextChildNodeToConsider = node;
+            m_nextChildNodeToConsider = element;
             m_currentSourceNode = 0;
         } else {
             // Otherwise the media element has neither a src attribute nor a source element
             // child: set the networkState to NETWORK_EMPTY, and abort these steps; the
             // synchronous section ends.
             m_loadState = WaitingForSource;
             setShouldDelayLoadEvent(false);
             m_networkState = NETWORK_EMPTY;
 
             WTF_LOG(Media, "HTMLMediaElement::selectMediaResource, nothing to load");
@@ skipping 418 matching lines @@
 
 void HTMLMediaElement::textTrackModeChanged(TextTrack* track)
 {
     if (track->trackType() == TextTrack::TrackElement) {
         // 4.8.10.12.3 Sourcing out-of-band text tracks
         // ... when a text track corresponding to a track element is created with text track
         // mode set to disabled and subsequently changes its text track mode to hidden, showing,
         // or showing by default for the first time, the user agent must immediately and synchronously
         // run the following algorithm ...
 
-        for (Node* node = firstChild(); node; node = node->nextSibling()) {
-            if (!node->hasTagName(trackTag))
+        for (Element* child = ElementTraversal::firstWithin(*this); child; child = ElementTraversal::nextSibling(*child)) {
+            if (!child->hasTagName(trackTag))
                 continue;
-            HTMLTrackElement* trackElement = toHTMLTrackElement(node);
+            HTMLTrackElement* trackElement = toHTMLTrackElement(child);
             if (trackElement->track() != track)
                 continue;
 
             // Mark this track as "configured" so configureTextTracks won't change the mode again.
             track->setHasBeenConfigured(true);
             if (track->mode() != TextTrack::disabledKeyword()) {
                 if (trackElement->readyState() == HTMLTrackElement::LOADED)
                     textTrackAddCues(track, track->cues());
 
                 // If this is the first added track, create the list of text tracks.
@@ skipping 208 matching lines @@
 
     // 6 - Abort the overall resource selection algorithm.
     m_currentSourceNode = 0;
 }
 
 void HTMLMediaElement::cancelPendingEventsAndCallbacks()
 {
     WTF_LOG(Media, "HTMLMediaElement::cancelPendingEventsAndCallbacks");
     m_asyncEventQueue->cancelAllEvents();
 
-    for (Node* node = firstChild(); node; node = node->nextSibling()) {
-        if (node->hasTagName(sourceTag))
-            toHTMLSourceElement(node)->cancelPendingErrorEvent();
+    for (Element* child = ElementTraversal::firstWithin(*this); child; child = ElementTraversal::nextSibling(*child)) {
+        if (child->hasTagName(sourceTag))
+            toHTMLSourceElement(child)->cancelPendingErrorEvent();
     }
 }
 
 void HTMLMediaElement::mediaPlayerNetworkStateChanged()
 {
     setNetworkState(m_player->networkState());
 }
 
 void HTMLMediaElement::mediaLoadingFailed(MediaPlayer::NetworkState error)
 {
@@ skipping 2482 matching lines @@
 {
     m_mediaSource->setWebMediaSourceAndOpen(adoptPtr(webMediaSource));
 }
 
 bool HTMLMediaElement::isInteractiveContent() const
 {
     return fastHasAttribute(controlsAttr);
 }
 
 }