Oilpan: have MediaController weakly refer to its media elements.

Source/core/html/MediaController.cpp

Index: Source/core/html/MediaController.cpp
diff --git a/Source/core/html/MediaController.cpp b/Source/core/html/MediaController.cpp
index 7835e2307a6efa23b6df4cd0c142aceec4d83362..0f2e3f33de9d09660f44e989f6fc248865c68223 100644
--- a/Source/core/html/MediaController.cpp
+++ b/Source/core/html/MediaController.cpp
@@ -38,9 +38,10 @@
 #include "wtf/StdLibExtras.h"
 #include "wtf/text/AtomicString.h"
 
-using namespace WebCore;
 using namespace std;
 
+namespace WebCore {
+
 PassRefPtrWillBeRawPtr<MediaController> MediaController::create(ExecutionContext* context)
 {
     return adoptRefWillBeRefCountedGarbageCollected(new MediaController(context));
@@ -73,7 +74,7 @@ void MediaController::addMediaElement(HTMLMediaElement* element)
     ASSERT(element);
     ASSERT(!m_mediaElements.contains(element));
 
-    m_mediaElements.append(element);
+    m_mediaElements.add(element);
     bringElementUpToSpeed(element);
 }
 
@@ -92,9 +93,10 @@ PassRefPtr<TimeRanges> MediaController::buffered() const
     // The buffered attribute must return a new static normalized TimeRanges object that represents
     // the intersection of the ranges of the media resources of the slaved media elements that the
     // user agent has buffered, at the time the attribute is evaluated.
-    RefPtr<TimeRanges> bufferedRanges = m_mediaElements.first()->buffered();
-    for (size_t index = 1; index < m_mediaElements.size(); ++index)
-        bufferedRanges->intersectWith(m_mediaElements[index]->buffered().get());
+    MediaElementSequence::const_iterator it = m_mediaElements.begin();
+    RefPtr<TimeRanges> bufferedRanges = (*it)->buffered();
+    for (++it; it != m_mediaElements.end(); ++it)
+        bufferedRanges->intersectWith((*it)->buffered().get());
     return bufferedRanges;
 }
 
@@ -106,9 +108,10 @@ PassRefPtr<TimeRanges> MediaController::seekable() const
     // The seekable attribute must return a new static normalized TimeRanges object that represents
     // the intersection of the ranges of the media resources of the slaved media elements that the
     // user agent is able to seek to, at the time the attribute is evaluated.
-    RefPtr<TimeRanges> seekableRanges = m_mediaElements.first()->seekable();
-    for (size_t index = 1; index < m_mediaElements.size(); ++index)
-        seekableRanges->intersectWith(m_mediaElements[index]->seekable().get());
+    MediaElementSequence::const_iterator it = m_mediaElements.begin();
+    RefPtr<TimeRanges> seekableRanges = (*it)->seekable();
+    for (++it; it != m_mediaElements.end(); ++it)
+        seekableRanges->intersectWith((*it)->seekable().get());
     return seekableRanges;
 }
 
@@ -120,9 +123,10 @@ PassRefPtr<TimeRanges> MediaController::played()
     // The played attribute must return a new static normalized TimeRanges object that represents
     // the union of the ranges of the media resources of the slaved media elements that the
     // user agent has so far rendered, at the time the attribute is evaluated.
-    RefPtr<TimeRanges> playedRanges = m_mediaElements.first()->played();
-    for (size_t index = 1; index < m_mediaElements.size(); ++index)
-        playedRanges->unionWith(m_mediaElements[index]->played().get());
+    MediaElementSequence::const_iterator it = m_mediaElements.begin();
+    RefPtr<TimeRanges> playedRanges = (*it)->played();
+    for (++it; it != m_mediaElements.end(); ++it)
+        playedRanges->unionWith((*it)->played().get());
     return playedRanges;
 }
 
@@ -131,8 +135,8 @@ double MediaController::duration() const
     // FIXME: Investigate caching the maximum duration and only updating the cached value
     // when the slaved media elements' durations change.
     double maxDuration = 0;
-    for (size_t index = 0; index < m_mediaElements.size(); ++index) {
-        double duration = m_mediaElements[index]->duration();
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it) {
+        double duration = (*it)->duration();
         if (std::isnan(duration))
             continue;
         maxDuration = max(maxDuration, duration);
@@ -170,8 +174,8 @@ void MediaController::setCurrentTime(double time, ExceptionState& exceptionState
     m_clock->setCurrentTime(time);
 
     // Seek each slaved media element to the new playback position relative to the media element timeline.
-    for (size_t index = 0; index < m_mediaElements.size(); ++index)
-        m_mediaElements[index]->seek(time, exceptionState);
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it)
+        (*it)->seek(time, exceptionState);
 
     scheduleTimeupdateEvent();
 }
@@ -194,8 +198,8 @@ void MediaController::play()
 {
     // When the play() method is invoked, the user agent must invoke the play method of each
     // slaved media element in turn,
-    for (size_t index = 0; index < m_mediaElements.size(); ++index)
-        m_mediaElements[index]->play();
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it)
+        (*it)->play();
 
     // and then invoke the unpause method of the MediaController.
     unpause();
@@ -242,8 +246,8 @@ void MediaController::setPlaybackRate(double rate)
     // playback rate to the new value,
     m_clock->setPlayRate(rate);
 
-    for (size_t index = 0; index < m_mediaElements.size(); ++index)
-        m_mediaElements[index]->updatePlaybackRate();
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it)
+        (*it)->updatePlaybackRate();
 
     // then queue a task to fire a simple event named ratechange at the MediaController.
     scheduleEvent(EventTypeNames::ratechange);
@@ -268,8 +272,8 @@ void MediaController::setVolume(double level, ExceptionState& exceptionState)
     // and queue a task to fire a simple event named volumechange at the MediaController.
     scheduleEvent(EventTypeNames::volumechange);
 
-    for (size_t index = 0; index < m_mediaElements.size(); ++index)
-        m_mediaElements[index]->updateVolume();
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it)
+        (*it)->updateVolume();
 }
 
 void MediaController::setMuted(bool flag)
@@ -284,8 +288,8 @@ void MediaController::setMuted(bool flag)
     // and queue a task to fire a simple event named volumechange at the MediaController.
     scheduleEvent(EventTypeNames::volumechange);
 
-    for (size_t index = 0; index < m_mediaElements.size(); ++index)
-        m_mediaElements[index]->updateVolume();
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it)
+        (*it)->updateVolume();
 }
 
 static const AtomicString& playbackStateWaiting()
@@ -357,9 +361,10 @@ void MediaController::updateReadyState()
     } else {
         // Otherwise, let it have the lowest value of the readyState IDL attributes of all of its
         // slaved media elements.
-        newReadyState = m_mediaElements.first()->readyState();
-        for (size_t index = 1; index < m_mediaElements.size(); ++index)
-            newReadyState = min(newReadyState, m_mediaElements[index]->readyState());
+        MediaElementSequence::const_iterator it = m_mediaElements.begin();
+        newReadyState = (*it)->readyState();
+        for (++it; it != m_mediaElements.end(); ++it)
+            newReadyState = min(newReadyState, (*it)->readyState());
     }
 
     if (newReadyState == oldReadyState)
@@ -467,8 +472,8 @@ void MediaController::updatePlaybackState()
 
 void MediaController::updateMediaElements()
 {
-    for (size_t index = 0; index < m_mediaElements.size(); ++index)
-        m_mediaElements[index]->updatePlayState();
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it)
+        (*it)->updatePlayState();
 }
 
 void MediaController::bringElementUpToSpeed(HTMLMediaElement* element)
@@ -493,8 +498,8 @@ bool MediaController::isRestrained() const
 
     bool anyAutoplayingAndPaused = false;
     bool allPaused = true;
-    for (size_t index = 0; index < m_mediaElements.size(); ++index) {
-        HTMLMediaElement* element = m_mediaElements[index];
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it) {
+        HTMLMediaElement* element = *it;
 
         // and none of its slaved media elements are blocked media elements,
         if (element->isBlocked())
@@ -523,8 +528,8 @@ bool MediaController::isBlocked() const
         return true;
 
     bool allPaused = true;
-    for (size_t index = 0; index < m_mediaElements.size(); ++index) {
-        HTMLMediaElement* element = m_mediaElements[index];
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it) {
+        HTMLMediaElement* element = *it;
 
         // or if any of its slaved media elements are blocked media elements,
         if (element->isBlocked())
@@ -555,8 +560,8 @@ bool MediaController::hasEnded() const
         return false;
 
     bool allHaveEnded = true;
-    for (size_t index = 0; index < m_mediaElements.size(); ++index) {
-        if (!m_mediaElements[index]->ended())
+    for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it) {
+        if (!(*it)->ended())
             allHaveEnded = false;
     }
     return allHaveEnded;
@@ -605,3 +610,11 @@ void MediaController::scheduleTimeupdateEvent()
     scheduleEvent(EventTypeNames::timeupdate);
     m_previousTimeupdateTime = now;
 }
+
+void MediaController::trace(Visitor* visitor)
+{
+    visitor->trace(m_mediaElements);
+    EventTargetWithInlineData::trace(visitor);
+}
+
+}