DevTools: Clean up character diff

third_party/WebKit/Source/devtools/front_end/externs.js

Index: third_party/WebKit/Source/devtools/front_end/externs.js
diff --git a/third_party/WebKit/Source/devtools/front_end/externs.js b/third_party/WebKit/Source/devtools/front_end/externs.js
index b2d0239c60dceb85847304eb71302adc0ff6b0d6..f6dc995f9781198520cdf6324071ef397f28ee24 100644
--- a/third_party/WebKit/Source/devtools/front_end/externs.js
+++ b/third_party/WebKit/Source/devtools/front_end/externs.js
@@ -357,7 +357,12 @@ diff_match_patch.prototype = {
    * @param {string} text2
    * @return {!Array.<!{0: number, 1: string}>}
    */
-  diff_main: function(text1, text2) {}
+  diff_main: function(text1, text2) {},
+
+  /**
+   * @param {!Array.<!{0: number, 1: string}>} diff
+   */
+  diff_cleanupSemantic(diff) {}
 };
 
 /** @constructor */