Deleting the defunct SearchBox interface.

Change-Id: Iecb698dbe942d3c9680ad1135ba0d604aa211856

Author: Selim Gurun

core/java/android/webkit/SearchBox.java

@@ -5363,13 +5363,6 @@ public void pasteFromClipboard() {
         }
     }
 
-    /**
-     * This is an implementation detail.
-     */
-    public SearchBox getSearchBox() {
-        return null;
-    }
-
     /**
      * Returns the currently highlighted text as a string.
      */