enhance ttml rendering (#1962)

Change-Id: Ifed3539e90649d259707a91fbd644fc58ba79b94

Author: valotvince

AUTHORS

@@ -14,6 +14,7 @@
 # Please keep the list sorted.
 
 AdsWizz <*@adswizz.com>
+Adrián Gómez Llorente <adgllorente@gmail.com>
 Alugha GmbH <*@alugha.com>
 Alvaro Velad Galvan <alvaro.velad@mirada.tv>
 Bonnier Broadcasting <*@bonnierbroadcasting.com>
@@ -52,4 +53,6 @@ Tomas Tichy <mr.tichyt@gmail.com>
 Toshihiro Suzuki <t.suzuki326@gmail.com>
 uStudio Inc. <*@ustudio.com>
 Verizon Digital Media Services <*@verizondigitalmedia.com>
-Adrián Gómez Llorente <adgllorente@gmail.com>
+Vincent Valot <valot.vince@gmail.com>
+
+

CONTRIBUTORS

@@ -83,5 +83,6 @@ Torbjörn Einarsson <torbjorn.einarsson@edgeware.tv>
 Toshihiro Suzuki <t.suzuki326@gmail.com>
 Vasanth Polipelli <vasanthap@google.com>
 Vignesh Venkatasubramanian <vigneshv@google.com>
+Vincent Valot <valot.vince@gmail.com>
 Yohann Connell <robinconnell@google.com>
 Adrián Gómez Llorente <adgllorente@gmail.com>

externs/shaka/text.js

@@ -349,6 +349,20 @@ shaka.extern.Cue.prototype.wrapLine;
  */
 shaka.extern.Cue.prototype.id;
 
+/**
+ * Nested cues
+ * @type {Array.<!shaka.extern.Cue>}
+ * @exportDoc
+ */
+shaka.extern.Cue.prototype.nestedCues;
+
+/**
+ * Whether or not the cue only acts as a spacer between two cues
+ * @type {boolean}
+ * @exportDoc
+ */
+shaka.extern.Cue.prototype.spacer;
+
 
 /**
  * An interface for plugins that parse text tracks.

lib/text/cue.js

@@ -184,6 +184,18 @@ shaka.text.Cue = function(startTime, endTime, payload) {
    * @exportInterface
    */
   this.id = '';
+
+  /**
+   * @override
+   * @exportInterface
+   */
+  this.nestedCues = [];
+
+  /**
+   * @override
+   * @exportInterface
+   */
+  this.spacer = false;
 };