Removed 'String::append' from some of the blink source.

Source/core/loader/FormSubmission.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 57 matching lines @@
         body = decodeURLEscapeSequences(body.replaceWithLiteral('&', "\r\n").replace('+', ' ') + "\r\n");
     }
 
     Vector<char> bodyData;
     bodyData.append("body=", 5);
     FormDataBuilder::encodeStringAsFormData(bodyData, body.utf8());
     body = String(bodyData.data(), bodyData.size()).replaceWithLiteral('+', "%20");
 
     String query = url.query();
     if (!query.isEmpty())
-        query.append('&');
-    query.append(body);
+        query = query + '&';
+    query = query + body;

[abarth-chromium, 2014/01/15 17:50:18]

Can we use StringBuilder here instead?

[Sunil Ratnu, 2014/01/16 05:49:56]

Thanks abarth!

Yes we can use StringBuilder here like this:

StringBuilder query;
query.append(url.query());
if (!query.isEmpty())
    query.append('&');
query.append(body);
url.setQuery(query.toString());

If that is fine with you, I will change it this way.

     url.setQuery(query);
 }
 
 void FormSubmission::Attributes::parseAction(const String& action)
 {
     // FIXME: Can we parse into a KURL?
     m_action = stripLeadingAndTrailingHTMLSpaces(action);
 }
 
 String FormSubmission::Attributes::parseEncodingType(const String& type)
@@ skipping 180 matching lines @@
             frameRequest.resourceRequest().setHTTPContentType(m_contentType);
         else
             frameRequest.resourceRequest().setHTTPContentType(m_contentType + "; boundary=" + m_boundary);
     }
 
     frameRequest.resourceRequest().setURL(requestURL());
     FrameLoader::addHTTPOriginIfNeeded(frameRequest.resourceRequest(), m_origin);
 }
 
 }