DevTools: Make TextEditor.tokenAtTextPosition() return exclusive end column

Source/devtools/front_end/sources/JavaScriptSourceFrame.js

Index: Source/devtools/front_end/sources/JavaScriptSourceFrame.js
diff --git a/Source/devtools/front_end/sources/JavaScriptSourceFrame.js b/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
index e8f536b163a05f698b6eb10ddfdf4a83bae862e9..43f21fee9a5cbfd1100fa5fdb6bf36ae05470b1a 100644
--- a/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
+++ b/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
@@ -515,14 +515,14 @@ WebInspector.JavaScriptSourceFrame.prototype = {
             return;
         var lineNumber = textPosition.startLine;
         var line = this.textEditor.line(lineNumber);
-        var tokenContent = line.substring(token.startColumn, token.endColumn + 1);
+        var tokenContent = line.substring(token.startColumn, token.endColumn);
 
         var isIdentifier = token.type.startsWith("js-variable") || token.type.startsWith("js-property") || token.type == "js-def";
         if (!isIdentifier && (token.type !== "js-keyword" || tokenContent !== "this"))
             return;
 
         var leftCorner = this.textEditor.cursorPositionToCoordinates(lineNumber, token.startColumn);
-        var rightCorner = this.textEditor.cursorPositionToCoordinates(lineNumber, token.endColumn + 1);
+        var rightCorner = this.textEditor.cursorPositionToCoordinates(lineNumber, token.endColumn);
         var anchorBox = new AnchorBox(leftCorner.x, leftCorner.y, rightCorner.x - leftCorner.x, leftCorner.height);
 
         anchorBox.highlight = {