Remove useless code

Author: bomsy

lib/source-map-consumer.js

@@ -801,22 +801,6 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
     return sources;
   }
 
-  /*
-  *
-  */
-  get x_google_ignoreList() {
-    const x_google_ignoreList = [];
-    for (let i = 0; i < this._sections.length; i++) {
-      const ignoreList = this._sections[i].consumer.x_google_ignoreList;
-      if (ignoreList) {
-        for (let j = 0; j < ignoreList.length; j++) {
-          x_google_ignoreList.push(ignoreList[j]);
-        }
-      }
-    }
-    return x_google_ignoreList;
-  }
-
   /**
    * Returns the original source, line, and column information for the generated
    * source's line and column positions provided. The only argument is an object