DevTools: Use CodeMirror modes instead of highlight tokenizers

Source/devtools/front_end/externs.js

Index: Source/devtools/front_end/externs.js
diff --git a/Source/devtools/front_end/externs.js b/Source/devtools/front_end/externs.js
index cf32051fdf3d8b362afbd6899193c60e91a35d03..adbaacc4d5427eca432a59b2bffe76e87a5a1251 100644
--- a/Source/devtools/front_end/externs.js
+++ b/Source/devtools/front_end/externs.js
@@ -501,6 +501,7 @@ CodeMirror.mimeModes = {};
 CodeMirror.getMode = function(options, spec) { };
 CodeMirror.overlayMode = function(mode1, mode2, squashSpans) { };
 CodeMirror.defineMode = function(modeName, modeConstructor) { };
+CodeMirror.startState = function(mode) { };
 
 /** @constructor */
 CodeMirror.Pos = function(line, ch) { }
@@ -510,7 +511,11 @@ CodeMirror.Pos.prototype.line;
 CodeMirror.Pos.prototype.ch;
 
 /** @constructor */
-CodeMirror.StringStream = function() { }
+CodeMirror.StringStream = function(line)
+{
+    this.pos = 0;
+    this.start = 0;
+}
 CodeMirror.StringStream.prototype = {
     backUp: function (n) { },
     column: function () { },