Fix corner-cases for WebVTT tokenizer escape handling

LayoutTests/media/track/track-webvtt-tc022-entities.html

Index: LayoutTests/media/track/track-webvtt-tc022-entities.html
diff --git a/LayoutTests/media/track/track-webvtt-tc022-entities.html b/LayoutTests/media/track/track-webvtt-tc022-entities.html
index b8e5b13b9af425ef163b4d31d09b58bf4a86e9d0..20d10c1a3c94f8503dfa095f3059c30926b8fae3 100644
--- a/LayoutTests/media/track/track-webvtt-tc022-entities.html
+++ b/LayoutTests/media/track/track-webvtt-tc022-entities.html
@@ -24,17 +24,18 @@
                 findMediaElement();
                 var expected = 
                 {
-                    length : 6,
+                    length : 7,
                     tests:
                     [
                         {
                             property : "getCueAsHTML().textContent",
-                            values : ["This cue has an amp & character.",
+                            values : ["This cue has an ampersand & character.",
                                       "This cue has a less than < character.",
                                       "This cue has a greater than > character.",
                                       "This cue has a Left-to-Right Mark \u200e.",
                                       "This cue has a Right-to-Left Mark \u200f.",
-                                      "This cue has a non-breaking space \u00a0."],
+                                      "This cue has a non-breaking space \u00a0.",
+                                      "This & is parsed to the same as &."],
                         },
                     ],
                 };
@@ -48,13 +49,12 @@
                 findMediaElement();
                 var expected = 
                 {
-                    length : 3,
+                    length : 2,
                     tests:
                     [
                         {
                             property : "getCueAsHTML().textContent",
-                            values : ["This cue has an amp character.\nAmpersand is ignored.",
-                                      "This cue has a less than ",
+                            values : ["This cue has a less than ",
                                       "This cue has a greater than > character.\nSince it's not related to a < character,\nit's just interpreted as text."],
                         },
                     ],