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

LayoutTests/inspector/editor/text-editor-token-at-position-expected.txt

Index: LayoutTests/inspector/editor/text-editor-token-at-position-expected.txt
diff --git a/LayoutTests/inspector/editor/text-editor-token-at-position-expected.txt b/LayoutTests/inspector/editor/text-editor-token-at-position-expected.txt
index 28aaecbf2285f975cb97de623d718acb0af29d5f..f008ffa78ab549d507109d7a7c5c6d050081419a 100644
--- a/LayoutTests/inspector/editor/text-editor-token-at-position-expected.txt
+++ b/LayoutTests/inspector/editor/text-editor-token-at-position-expected.txt
@@ -3,17 +3,17 @@ Test editor tokenAtTextPosition method.
 
 Running: testHighlightedText
 Line: function foo(a, b) {
-Column #0 (char 'f') - token: {"startColumn":0,"endColumn":7,"type":"js-keyword"}
-Column #10 (char 'o') - token: {"startColumn":9,"endColumn":11,"type":"js-variable"}
-Column #13 (char 'a') - token: {"startColumn":13,"endColumn":13,"type":"js-def"}
+Column #0 (char 'f') - token: {"startColumn":0,"endColumn":8,"type":"js-keyword"}
+Column #10 (char 'o') - token: {"startColumn":9,"endColumn":12,"type":"js-variable"}
+Column #13 (char 'a') - token: {"startColumn":13,"endColumn":14,"type":"js-def"}
 Line:     var f = /.a/.test(a); /*
-Column #8 (char 'f') - token: {"startColumn":8,"endColumn":8,"type":"js-def"}
-Column #14 (char 'a') - token: {"startColumn":12,"endColumn":15,"type":"js-string-2"}
-Column #19 (char 's') - token: {"startColumn":17,"endColumn":20,"type":"js-property"}
+Column #8 (char 'f') - token: {"startColumn":8,"endColumn":9,"type":"js-def"}
+Column #14 (char 'a') - token: {"startColumn":12,"endColumn":16,"type":"js-string-2"}
+Column #19 (char 's') - token: {"startColumn":17,"endColumn":21,"type":"js-property"}
 Line: this is a comment */
-Column #0 (char 't') - token: {"startColumn":0,"endColumn":19,"type":"js-comment"}
-Column #5 (char 'i') - token: {"startColumn":0,"endColumn":19,"type":"js-comment"}
+Column #0 (char 't') - token: {"startColumn":0,"endColumn":20,"type":"js-comment"}
+Column #5 (char 'i') - token: {"startColumn":0,"endColumn":20,"type":"js-comment"}
 Line:     return f + "looongword";
-Column #5 (char 'e') - token: {"startColumn":4,"endColumn":9,"type":"js-keyword"}
-Column #20 (char 'n') - token: {"startColumn":15,"endColumn":26,"type":"js-string"}
+Column #5 (char 'e') - token: {"startColumn":4,"endColumn":10,"type":"js-keyword"}
+Column #20 (char 'n') - token: {"startColumn":15,"endColumn":27,"type":"js-string"}