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

Source/core/fetch/ScriptResource.cpp

Index: Source/core/fetch/ScriptResource.cpp
diff --git a/Source/core/fetch/ScriptResource.cpp b/Source/core/fetch/ScriptResource.cpp
old mode 100644
new mode 100755
index 873ef3322722f711ff22d971252932b792fd5174..8dbc2d3f4da91642bd8835924fc471a86b35ddfe
--- a/Source/core/fetch/ScriptResource.cpp
+++ b/Source/core/fetch/ScriptResource.cpp
@@ -71,8 +71,7 @@ const String& ScriptResource::script()
     ASSERT(isLoaded());
 
     if (!m_script && m_data) {
-        String script = m_decoder->decode(m_data->data(), encodedSize());
-        script.append(m_decoder->flush());
+        String script = m_decoder->decode(m_data->data(), encodedSize()) + m_decoder->flush();
         m_data.clear();
         // We lie a it here and claim that script counts as encoded data (even though it's really decoded data).
         // That's because the MemoryCache thinks that it can clear out decoded data by calling destroyDecodedData(),