Removed usage of RefPtr::Release in unit tests

third_party/WebKit/Source/web/tests/MHTMLTest.cpp

 /*
  * Copyright (C) 2014 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 154 matching lines @@
     }
     MHTMLArchive::GenerateMHTMLFooterForTesting(boundary,
                                                 *mhtml_data->MutableData());
 
     // Validate the generated MHTML.
     MHTMLParser parser(
         SharedBuffer::Create(mhtml_data->data(), mhtml_data->length()));
     EXPECT_FALSE(parser.ParseArchive().IsEmpty())
         << "Generated MHTML is malformed";
 
-    return mhtml_data.Release();
+    return mhtml_data;
   }
 
   PassRefPtr<RawData> Serialize(const char* title,
                                 const char* mime,
                                 MHTMLArchive::EncodingPolicy encoding_policy) {
     return GenerateMHTMLData(resources_, encoding_policy, title, mime);
   }
 
  private:
   PassRefPtr<SharedBuffer> ReadFile(const char* file_name) {
@@ skipping 145 matching lines @@
                   .getElementById("s1"));
   // The element to be created by the script in the shadow dom template is
   // not found because the script is blocked.
   EXPECT_FALSE(document->getElementById("h4")
                    ->Shadow()
                    ->OldestShadowRoot()
                    .getElementById("s2"));
 }
 
 }  // namespace blink