Update poster code as per https://html.spec.whatwg.org/#show-poster-flag

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

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index 614c6ce029563ab390b6395af1f1e283eed2f81d..8177a4dee6d3f426a581de3a4dfe387a724fd673 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -314,7 +314,6 @@ HTMLMediaElement::HTMLMediaElement(const QualifiedName& tagName, Document& docum
     , m_deferredLoadState(NotDeferred)
     , m_deferredLoadTimer(this, &HTMLMediaElement::deferredLoadTimerFired)
     , m_webLayer(nullptr)
-    , m_displayMode(Unknown)
     , m_cachedTime(std::numeric_limits<double>::quiet_NaN())
     , m_fragmentEndTime(std::numeric_limits<double>::quiet_NaN())
     , m_pendingActionFlags(0)
@@ -737,7 +736,6 @@ void HTMLMediaElement::prepareForLoad()
     m_haveFiredLoadedData = false;
     m_completelyLoaded = false;
     m_havePreparedToPlay = false;
-    m_displayMode = Unknown;
 
     // 1 - Abort any already-running instance of the resource selection algorithm for this element.
     m_loadState = WaitingForSource;
@@ -804,10 +802,11 @@ void HTMLMediaElement::prepareForLoad()
     // 8 - Note: Playback of any previously playing media resource for this element stops.
 
     // The resource selection algorithm
-    // 1 - Set the networkState to NETWORK_NO_SOURCE
+    // 1 - Set the element's networkState attribute to the NETWORK_NO_SOURCE value.
     m_networkState = NETWORK_NO_SOURCE;
 
-    // 2 - Asynchronously await a stable state.
+    // 2 - Set the element's show poster flag to true.
+    setShowPoster(true);
 
     m_playedTimeRanges = TimeRanges::create();
 
@@ -816,12 +815,12 @@ void HTMLMediaElement::prepareForLoad()
     m_lastSeekTime = 0;
     m_duration = std::numeric_limits<double>::quiet_NaN();
 
-    // The spec doesn't say to block the load event until we actually run the asynchronous section
-    // algorithm, but do it now because we won't start that until after the timer fires and the
-    // event may have already fired by then.
+    // 3 - Set the media element's delaying-the-load-event flag to true (this delays the load event).
     setShouldDelayLoadEvent(true);
     if (mediaControls())
         mediaControls()->reset();
+
+    // 4 - Await a stable state, allowing the task that invoked this algorithm to continue.
 }
 
 void HTMLMediaElement::loadInternal()
@@ -863,7 +862,6 @@ void HTMLMediaElement::selectMediaResource()
             m_loadState = WaitingForSource;
             setShouldDelayLoadEvent(false);
             m_networkState = NETWORK_EMPTY;
-            updateDisplayState();
 
             WTF_LOG(Media, "HTMLMediaElement::selectMediaResource(%p), nothing to load", this);
             return;
@@ -954,9 +952,6 @@ void HTMLMediaElement::loadResource(const KURL& url, ContentType& contentType, c
 
     startProgressEventTimer();
 
-    // Reset display mode to force a recalculation of what to show because we are resetting the player.
-    setDisplayMode(Unknown);
-
     setPlayerPreload();
 
     if (fastHasAttribute(mutedAttr))
@@ -997,10 +992,6 @@ void HTMLMediaElement::loadResource(const KURL& url, ContentType& contentType, c
         mediaLoadingFailed(WebMediaPlayer::NetworkStateFormatError);
     }
 
-    // If there is no poster to display, allow the media engine to render video frames as soon as
-    // they are available.
-    updateDisplayState();
-
     if (layoutObject())
         layoutObject()->updateFromElement();
 }
@@ -1248,10 +1239,11 @@ void HTMLMediaElement::waitForSourceChange()
     // 6.17 - Waiting: Set the element's networkState attribute to the NETWORK_NO_SOURCE value
     m_networkState = NETWORK_NO_SOURCE;
 
-    // 6.18 - Set the element's delaying-the-load-event flag to false. This stops delaying the load event.
-    setShouldDelayLoadEvent(false);
+    // 6.18 - Set the element's show poster flag to true
+    setShowPoster(true);
 
-    updateDisplayState();
+    // 6.19 - Queue a task to set the element's delaying-the-load-event flag to false. This stops delaying the load event.
+    setShouldDelayLoadEvent(false);
 
     if (layoutObject())
         layoutObject()->updateFromElement();
@@ -1265,32 +1257,35 @@ void HTMLMediaElement::noneSupported()
     m_loadState = WaitingForSource;
     m_currentSourceNode = nullptr;
 
-    // 4.8.10.5
+    // 4.8.13.5
     // 6 - Reaching this step indicates that the media resource failed to load or that the given
-    // URL could not be resolved. In one atomic operation, run the following steps:
+    // URL could not be resolved.  Queue a task to run the dedicated media source failure steps.
 
     // 6.1 - Set the error attribute to a new MediaError object whose code attribute is set to
     // MEDIA_ERR_SRC_NOT_SUPPORTED.
     m_error = MediaError::create(MediaError::MEDIA_ERR_SRC_NOT_SUPPORTED);
 
-    // 6.2 - Forget the media element's media-resource-specific text tracks.
+    // 6.2 - Forget the media element's media-resource-specific tracks.
     forgetResourceSpecificTracks();
 
     // 6.3 - Set the element's networkState attribute to the NETWORK_NO_SOURCE value.
     m_networkState = NETWORK_NO_SOURCE;
 
-    // 7 - Queue a task to fire a simple event named error at the media element.
+    // 6.4 - Set the element's show poster flag to true.
+    setShowPoster(true);
+
+    // 6.5 - Fire a simple event named error at the media element.
     scheduleEvent(EventTypeNames::error);
 
     closeMediaSource();
 
-    // 8 - Set the element's delaying-the-load-event flag to false. This stops delaying the load event.
+    // 6.6 - Set the element's delaying-the-load-event flag to false. This stops delaying the load event.
     setShouldDelayLoadEvent(false);
 
-    // 9 - Abort these steps. Until the load() method is invoked or the src attribute is changed,
-    // the element won't attempt to load another resource.
+    // 7 - Wait for the task queued by the previous step to have executed.
 
-    updateDisplayState();
+    // 8 - Abort these steps. The element won't attempt to load
+    // another resource until this algorithm is triggered again.
 
     if (layoutObject())
         layoutObject()->updateFromElement();
@@ -1376,7 +1371,6 @@ void HTMLMediaElement::mediaLoadingFailed(WebMediaPlayer::NetworkState error)
         && m_loadState == LoadingFromSrcAttr)
         noneSupported();
 
-    updateDisplayState();
     if (mediaControls())
         mediaControls()->reset();
 }
@@ -1568,6 +1562,7 @@ void HTMLMediaElement::setReadyState(ReadyState state)
 
             if (!m_userGestureRequiredForPlay) {
                 m_paused = false;
+                setShowPoster(false);
                 invalidateCachedTime();
                 scheduleEvent(EventTypeNames::play);
                 scheduleEvent(EventTypeNames::playing);
@@ -1580,7 +1575,6 @@ void HTMLMediaElement::setReadyState(ReadyState state)
     }
 
     if (shouldUpdateDisplayState) {
-        updateDisplayState();
         if (mediaControls())
             mediaControls()->refreshClosedCaptionsButtonVisibility();
     }
@@ -1639,6 +1633,8 @@ void HTMLMediaElement::seek(double time)
 {
     WTF_LOG(Media, "HTMLMediaElement::seek(%p, %f)", this, time);
 
+    // 1 - Set the media element's show poster flag to false.
+    setShowPoster(false);
     // 2 - If the media element's readyState is HAVE_NOTHING, abort these steps.
     if (m_readyState == HAVE_NOTHING)
         return;
@@ -1721,8 +1717,6 @@ void HTMLMediaElement::finishSeek()
 
     // 17 - Queue a task to fire a simple event named seeked at the element.
     scheduleEvent(EventTypeNames::seeked);
-
-    setDisplayMode(Video);
 }
 
 HTMLMediaElement::ReadyState HTMLMediaElement::readyState() const
@@ -2010,6 +2004,7 @@ void HTMLMediaElement::playInternal()
 
     if (m_paused) {
         m_paused = false;
+        setShowPoster(false);
         invalidateCachedTime();
         scheduleEvent(EventTypeNames::play);
 
@@ -2875,7 +2870,6 @@ void HTMLMediaElement::repaint()
     if (m_webLayer)
         m_webLayer->invalidate();
 
-    updateDisplayState();
     if (layoutObject())
         layoutObject()->setShouldDoFullPaintInvalidation();
 }
@@ -2988,7 +2982,6 @@ void HTMLMediaElement::updatePlayState()
         this, boolString(shouldBePlaying), boolString(isPlaying));
 
     if (shouldBePlaying) {
-        setDisplayMode(Video);
         invalidateCachedTime();
 
         if (!isPlaying) {
@@ -3053,12 +3046,13 @@ void HTMLMediaElement::userCancelledLoad()
     // 3 - Queue a task to fire a simple event named error at the media element.
     scheduleEvent(EventTypeNames::abort);
 
-    // 4 - If the media element's readyState attribute has a value equal to HAVE_NOTHING, set the
-    // element's networkState attribute to the NETWORK_EMPTY value and queue a task to fire a
-    // simple event named emptied at the element. Otherwise, set the element's networkState
-    // attribute to the NETWORK_IDLE value.
+    // 4 - If the media element's readyState attribute has a value equal to HAVE_NOTHING,
+    // set the element's networkState attribute to the NETWORK_EMPTY value set the element's
+    // show poster flag to true, and fire a simple event named emptied at the element.
+    // Otherwise, set the element's networkState attribute to the NETWORK_IDLE value.
     if (m_readyState == HAVE_NOTHING) {
         m_networkState = NETWORK_EMPTY;
+        setShowPoster(true);
         scheduleEvent(EventTypeNames::emptied);
     } else {
         m_networkState = NETWORK_IDLE;