Media Controls: use loadedmetadata and error events.

This is temporarily using ::reset() to guarantee backward compatibility
and reduce chances of breakage for now.

BUG=662761
R=zqzhang@chromium.org

Review-Url: https://codereview.chromium.org/2589873002
Cr-Commit-Position: refs/heads/master@{#439503}

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

@@ -1488,18 +1488,17 @@ void HTMLMediaElement::mediaLoadingFailed(WebMediaPlayer::NetworkState error) {
   }
 
   if (error == WebMediaPlayer::NetworkStateNetworkError &&
-      m_readyState >= kHaveMetadata)
+      m_readyState >= kHaveMetadata) {
     mediaEngineError(MediaError::create(MediaError::kMediaErrNetwork));
-  else if (error == WebMediaPlayer::NetworkStateDecodeError)
+  } else if (error == WebMediaPlayer::NetworkStateDecodeError) {
     mediaEngineError(MediaError::create(MediaError::kMediaErrDecode));
-  else if ((error == WebMediaPlayer::NetworkStateFormatError ||
-            error == WebMediaPlayer::NetworkStateNetworkError) &&
-           m_loadState == LoadingFromSrcAttr)
+  } else if ((error == WebMediaPlayer::NetworkStateFormatError ||
+              error == WebMediaPlayer::NetworkStateNetworkError) &&
+             m_loadState == LoadingFromSrcAttr) {
     noneSupported();
+  }
 
   updateDisplayState();
-  if (mediaControls())
-    mediaControls()->reset();
 }
 
 void HTMLMediaElement::setNetworkState(WebMediaPlayer::NetworkState state) {
@@ -1658,8 +1657,6 @@ void HTMLMediaElement::setReadyState(ReadyState state) {
       jumped = true;
     }
 
-    if (mediaControls())
-      mediaControls()->reset();
     if (layoutObject())
       layoutObject()->updateFromElement();
   }
@@ -3852,11 +3849,12 @@ bool HTMLMediaElement::isAutoplayAllowedPerSettings() const {
 }
 
 void HTMLMediaElement::setNetworkState(NetworkState state) {
-  if (m_networkState != state) {
-    m_networkState = state;
-    if (MediaControls* controls = mediaControls())
-      controls->networkStateChanged();
-  }
+  if (m_networkState == state)
+    return;
+
+  m_networkState = state;
+  if (mediaControls())
+    mediaControls()->networkStateChanged();
 }
 
 void HTMLMediaElement::videoWillBeDrawnToCanvas() const {

third_party/WebKit/Source/core/html/shadow/MediaControls.cpp

@@ -748,6 +748,18 @@ void MediaControls::onTextTracksChanged() {
   m_toggleClosedCaptionsButton->updateDisplayType();
 }
 
+void MediaControls::onError() {
+  // TODO(mlamouri): we should only change the aspects of the control that need
+  // to be changed.
+  reset();
+}
+
+void MediaControls::onLoadedMetadata() {
+  // TODO(mlamouri): we should only change the aspects of the control that need
+  // to be changed.
+  reset();
+}
+
 void MediaControls::notifyPanelWidthChanged(const LayoutUnit& newWidth) {
   // Don't bother to do any work if this matches the most recent panel
   // width, since we're called after layout.

third_party/WebKit/Source/core/html/shadow/MediaControls.h

@@ -160,6 +160,8 @@ class CORE_EXPORT MediaControls final : public HTMLDivElement {
   void onPause();
   void onTextTracksAddedOrRemoved();
   void onTextTracksChanged();
+  void onError();
+  void onLoadedMetadata();
 
   Member<HTMLMediaElement> m_mediaElement;
 

third_party/WebKit/Source/core/html/shadow/MediaControlsMediaEventListener.cpp

@@ -26,6 +26,10 @@ MediaControlsMediaEventListener::MediaControlsMediaEventListener(
                                                     false);
   m_mediaControls->m_mediaElement->addEventListener(
       EventTypeNames::durationchange, this, false);
+  m_mediaControls->m_mediaElement->addEventListener(EventTypeNames::error, this,
+                                                    false);
+  m_mediaControls->m_mediaElement->addEventListener(
+      EventTypeNames::loadedmetadata, this, false);
 
   // TextTracks events.
   TextTrackList* textTracks = m_mediaControls->m_mediaElement->textTracks();
@@ -66,6 +70,14 @@ void MediaControlsMediaEventListener::handleEvent(
     m_mediaControls->onPause();
     return;
   }
+  if (event->type() == EventTypeNames::error) {
+    m_mediaControls->onError();
+    return;
+  }
+  if (event->type() == EventTypeNames::loadedmetadata) {
+    m_mediaControls->onLoadedMetadata();
+    return;
+  }
 
   // TextTracks events.
   if (event->type() == EventTypeNames::addtrack ||