Use Traversal<HTMLSourceElement> to find the next source candidate

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 fc8703819fa07c010facb070678d03f1f8120be2..d7565bb8e95c7a65cc174d6077ce4796a5a37240 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -711,7 +711,7 @@ void HTMLMediaElement::prepareForLoad()
 
     // 1 - Abort any already-running instance of the resource selection algorithm for this element.
     m_loadState = WaitingForSource;
-    m_currentSourceNode = nullptr;
+    m_currentSourceElement = nullptr;
 
     // 2 - If there are any tasks from the media element's media element event task source in
     // one of the task queues, then remove those tasks.
@@ -826,8 +826,8 @@ void HTMLMediaElement::selectMediaResource()
         // source element child in tree order.
         if (HTMLSourceElement* element = Traversal<HTMLSourceElement>::firstChild(*this)) {
             mode = children;
-            m_nextChildNodeToConsider = element;
-            m_currentSourceNode = nullptr;
+            m_nextSourceElement = element;
+            m_currentSourceElement = nullptr;
         } 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
@@ -1543,7 +1543,7 @@ void HTMLMediaElement::noneSupported()
 
     stopPeriodicTimers();
     m_loadState = WaitingForSource;
-    m_currentSourceNode = nullptr;
+    m_currentSourceElement = nullptr;
 
     // 4.8.10.5
     // 6 - Reaching this step indicates that the media resource failed to load or that the given
@@ -1599,7 +1599,7 @@ void HTMLMediaElement::mediaEngineError(PassRefPtrWillBeRawPtr<MediaError> err)
     setShouldDelayLoadEvent(false);
 
     // 6 - Abort the overall resource selection algorithm.
-    m_currentSourceNode = nullptr;
+    m_currentSourceElement = nullptr;
 }
 
 void HTMLMediaElement::cancelPendingEventsAndCallbacks()
@@ -1626,8 +1626,8 @@ void HTMLMediaElement::mediaLoadingFailed(MediaPlayer::NetworkState error)
 
         // resource selection algorithm
         // Step 9.Otherwise.9 - Failed with elements: Queue a task, using the DOM manipulation task source, to fire a simple event named error at the candidate element.
-        if (m_currentSourceNode)
-            m_currentSourceNode->scheduleErrorEvent();
+        if (m_currentSourceElement)
+            m_currentSourceElement->scheduleErrorEvent();
         else
             WTF_LOG(Media, "HTMLMediaElement::setNetworkState - error event not sent, <source> was removed");
 
@@ -2830,13 +2830,13 @@ bool HTMLMediaElement::havePotentialSourceChild()
 {
     // Stash the current <source> node and next nodes so we can restore them after checking
     // to see there is another potential.
-    RefPtrWillBeRawPtr<HTMLSourceElement> currentSourceNode = m_currentSourceNode;
-    RefPtrWillBeRawPtr<Node> nextNode = m_nextChildNodeToConsider;
+    RefPtrWillBeRawPtr<HTMLSourceElement> currentSourceElement = m_currentSourceElement;
+    RefPtrWillBeRawPtr<HTMLSourceElement> nextSourceElement = m_nextSourceElement;
 
     KURL nextURL = selectNextSourceChild(0, 0, DoNothing);
 
-    m_currentSourceNode = currentSourceNode;
-    m_nextChildNodeToConsider = nextNode;
+    m_currentSourceElement = currentSourceElement;
+    m_nextSourceElement = nextSourceElement;
 
     return nextURL.isValid();
 }
@@ -2850,7 +2850,7 @@ KURL HTMLMediaElement::selectNextSourceChild(ContentType* contentType, String* k
         WTF_LOG(Media, "HTMLMediaElement::selectNextSourceChild");
 #endif
 
-    if (!m_nextChildNodeToConsider) {
+    if (!m_nextSourceElement) {
 #if !LOG_DISABLED
         if (shouldLog)
             WTF_LOG(Media, "HTMLMediaElement::selectNextSourceChild -> 0x0000, \"\"");
@@ -2863,7 +2863,7 @@ KURL HTMLMediaElement::selectNextSourceChild(ContentType* contentType, String* k
     HTMLSourceElement* source = 0;
     String type;
     String system;
-    bool lookingForStartNode = m_nextChildNodeToConsider;
+    bool lookingForStartNode = m_nextSourceElement;
     bool canUseSourceElement = false;
 
     NodeVector potentialSourceNodes;
@@ -2871,7 +2871,7 @@ KURL HTMLMediaElement::selectNextSourceChild(ContentType* contentType, String* k
 
     for (unsigned i = 0; !canUseSourceElement && i < potentialSourceNodes.size(); ++i) {
         node = potentialSourceNodes[i].get();
-        if (lookingForStartNode && m_nextChildNodeToConsider != node)
+        if (lookingForStartNode && m_nextSourceElement != node)
             continue;
         lookingForStartNode = false;
 
@@ -2921,16 +2921,16 @@ check_again:
             *contentType = ContentType(type);
         if (keySystem)
             *keySystem = system;
-        m_currentSourceNode = source;
-        m_nextChildNodeToConsider = source->nextSibling();
+        m_currentSourceElement = source;
+        m_nextSourceElement = Traversal<HTMLSourceElement>::nextSibling(*source);
     } else {
-        m_currentSourceNode = nullptr;
-        m_nextChildNodeToConsider = nullptr;
+        m_currentSourceElement = nullptr;
+        m_nextSourceElement = nullptr;
     }
 
 #if !LOG_DISABLED
     if (shouldLog)
-        WTF_LOG(Media, "HTMLMediaElement::selectNextSourceChild -> %p, %s", m_currentSourceNode.get(), canUseSourceElement ? urlForLoggingMedia(mediaURL).utf8().data() : "");
+        WTF_LOG(Media, "HTMLMediaElement::selectNextSourceChild -> %p, %s", m_currentSourceElement.get(), canUseSourceElement ? urlForLoggingMedia(mediaURL).utf8().data() : "");
 #endif
     return canUseSourceElement ? mediaURL : KURL();
 }
@@ -2953,17 +2953,17 @@ void HTMLMediaElement::sourceWasAdded(HTMLSourceElement* source)
     // the media element's resource selection algorithm.
     if (networkState() == HTMLMediaElement::NETWORK_EMPTY) {
         scheduleDelayedAction(LoadMediaResource);
-        m_nextChildNodeToConsider = source;
+        m_nextSourceElement = source;
         return;
     }
 
-    if (m_currentSourceNode && source == m_currentSourceNode->nextSibling()) {
+    if (m_currentSourceElement && source == Traversal<HTMLSourceElement>::nextSibling(*m_currentSourceElement)) {
         WTF_LOG(Media, "HTMLMediaElement::sourceWasAdded - <source> inserted immediately after current source");
-        m_nextChildNodeToConsider = source;
+        m_nextSourceElement = source;
         return;
     }
 
-    if (m_nextChildNodeToConsider)
+    if (m_nextSourceElement)
         return;
 
     // 4.8.9.5, resource selection algorithm, source elements section:
@@ -2977,7 +2977,7 @@ void HTMLMediaElement::sourceWasAdded(HTMLSourceElement* source)
     m_networkState = NETWORK_LOADING;
 
     // 25. Jump back to the find next candidate step above.
-    m_nextChildNodeToConsider = source;
+    m_nextSourceElement = source;
     scheduleNextSourceChild();
 }
 
@@ -2990,19 +2990,19 @@ void HTMLMediaElement::sourceWasRemoved(HTMLSourceElement* source)
     WTF_LOG(Media, "HTMLMediaElement::sourceWasRemoved - 'src' is %s", urlForLoggingMedia(url).utf8().data());
 #endif
 
-    if (source != m_currentSourceNode && source != m_nextChildNodeToConsider)
+    if (source != m_currentSourceElement && source != m_nextSourceElement)
         return;
 
-    if (source == m_nextChildNodeToConsider) {
-        if (m_currentSourceNode)
-            m_nextChildNodeToConsider = m_currentSourceNode->nextSibling();
-        WTF_LOG(Media, "HTMLMediaElement::sourceRemoved - m_nextChildNodeToConsider set to %p", m_nextChildNodeToConsider.get());
-    } else if (source == m_currentSourceNode) {
-        // Clear the current source node pointer, but don't change the movie as the spec says:
+    if (source == m_nextSourceElement) {
+        if (m_currentSourceElement)
+            m_nextSourceElement = Traversal<HTMLSourceElement>::nextSibling(*m_currentSourceElement);
+        WTF_LOG(Media, "HTMLMediaElement::sourceRemoved - m_nextSourceElement set to %p", m_nextSourceElement.get());
+    } else if (source == m_currentSourceElement) {
+        // Clear the current source element pointer, but don't change the movie as the spec says:
         // 4.8.8 - Dynamically modifying a source element and its attribute when the element is already
         // inserted in a video or audio element will have no effect.
-        m_currentSourceNode = nullptr;
-        WTF_LOG(Media, "HTMLMediaElement::sourceRemoved - m_currentSourceNode set to 0");
+        m_currentSourceElement = nullptr;
+        WTF_LOG(Media, "HTMLMediaElement::sourceRemoved - m_currentSourceElement set to 0");
     }
 }
 
@@ -3365,7 +3365,7 @@ void HTMLMediaElement::userCancelledLoad()
     setShouldDelayLoadEvent(false);
 
     // 6 - Abort the overall resource selection algorithm.
-    m_currentSourceNode = nullptr;
+    m_currentSourceElement = nullptr;
 
     // Reset m_readyState since m_player is gone.
     m_readyState = HAVE_NOTHING;
@@ -3914,8 +3914,8 @@ void HTMLMediaElement::trace(Visitor* visitor)
 {
     visitor->trace(m_asyncEventQueue);
     visitor->trace(m_error);
-    visitor->trace(m_currentSourceNode);
-    visitor->trace(m_nextChildNodeToConsider);
+    visitor->trace(m_currentSourceElement);
+    visitor->trace(m_nextSourceElement);
     visitor->trace(m_audioTracks);
     visitor->trace(m_videoTracks);
     visitor->trace(m_textTracks);