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 2724673c86ed5b77c9e4b788b8ad6aa2393ce6fd..368f20e4948762755b9df9a144730d2da84dc2a9
--- a/Source/core/fetch/ScriptResource.cpp
+++ b/Source/core/fetch/ScriptResource.cpp
@@ -72,7 +72,7 @@ const String& ScriptResource::script()
 
     if (!m_script && m_data) {
         String script = m_decoder->decode(m_data->data(), encodedSize());
-        script.append(m_decoder->flush());
+        script = script + 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(),