Support text track selection in video controls

LayoutTests/media/media-controls.js

Index: LayoutTests/media/media-controls.js
diff --git a/LayoutTests/media/media-controls.js b/LayoutTests/media/media-controls.js
index eb96ca8c85a578b982d225581f7f1e0f0d0dc993..ad46ae44780e59000ef4ccb7583a0a4cce23b5ea 100644
--- a/LayoutTests/media/media-controls.js
+++ b/LayoutTests/media/media-controls.js
@@ -47,13 +47,18 @@ function mediaControlsButton(element, id)
     return button;
 }
 
+function elementCoordinates(element)
+{
+    var elementBoundingRect = element.getBoundingClientRect();
+    var x = elementBoundingRect.left + elementBoundingRect.width / 2;
+    var y = elementBoundingRect.top + elementBoundingRect.height / 2;
+    return new Array(x, y);
+}
+
 function mediaControlsButtonCoordinates(element, id)
 {
     var button = mediaControlsButton(element, id);
-    var buttonBoundingRect = button.getBoundingClientRect();
-    var x = buttonBoundingRect.left + buttonBoundingRect.width / 2;
-    var y = buttonBoundingRect.top + buttonBoundingRect.height / 2;
-    return new Array(x, y);
+    return elementCoordinates(button);
 }
 
 function mediaControlsButtonDimensions(element, id)
@@ -119,14 +124,48 @@ function testClosedCaptionsButtonVisibility(expected)
     }
 }
 
-function clickCCButton()
+function clickAtCoordinates(x, y)
 {
-    consoleWrite("*** Click the CC button.");
-    eventSender.mouseMoveTo(captionsButtonCoordinates[0], captionsButtonCoordinates[1]);
+    eventSender.mouseMoveTo(x, y);
     eventSender.mouseDown();
     eventSender.mouseUp();
 }
 
+function clickCCButton()
+{
+    consoleWrite("*** Click the CC button.");
+    clickAtCoordinates(captionsButtonCoordinates[0], captionsButtonCoordinates[1]);
+}
+
+function textTrackListItem(video, index)
+{
+    var textTrackListElementID = "-internal-media-controls-text-track-list";
+    var textTrackListElement = mediaControlsElement(internals.shadowRoot(video).firstChild, textTrackListElementID);
+    if (!textTrackListElement)
+        throw "Failed to find text track list element";
+
+    var tracksSectionElement = textTrackListElement.lastChild;
+    var trackListItems = tracksSectionElement.childNodes;
+    for (var i = 0; i < trackListItems.length; i++) {
+        var trackListItem = trackListItems[i];
+        if (trackListItem.firstChild.getAttribute("data-webkit-track-index") == index)
+            return trackListItem;
+    }
+}
+
+function selectTextTrack(video, index)
+{
+    clickCCButton();
+    var trackListItemElement = textTrackListItem(video, index);
+    var trackListItemCoordinates = elementCoordinates(trackListItemElement);
+    clickAtCoordinates(trackListItemCoordinates[0], trackListItemCoordinates[1]);
+}
+
+function turnClosedCaptionsOff(video)
+{
+    selectTextTrack(video, -1);
+}
+
 function runAfterHideMediaControlsTimerFired(func, mediaElement)
 {
     if (mediaElement.paused)