Removing duplicate 'using namespace blink;' in platform and web

Source/platform/image-decoders/gif/GIFImageDecoderTest.cpp

 /*
  * Copyright (C) 2013 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 26 matching lines @@
 #include "public/platform/WebData.h"
 #include "public/platform/WebSize.h"
 #include "public/platform/WebUnitTestSupport.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/StringHasher.h"
 #include "wtf/Vector.h"
 #include <gtest/gtest.h>
 
 using namespace blink;
-using namespace blink;
 
 namespace {
 
 PassRefPtr<SharedBuffer> readFile(const char* fileName)
 {
     String filePath = Platform::current()->unitTestSupport()->webKitRootDir();
     filePath.append(fileName);
 
     return Platform::current()->unitTestSupport()->readFromFile(filePath);
 }
@@ skipping 435 matching lines @@
     RefPtr<SharedBuffer> data = readFile("/Source/web/tests/data/invalid-disposal-method.gif");
     ASSERT_TRUE(data.get());
     decoder->setData(data.get(), true);
 
     EXPECT_EQ(2u, decoder->frameCount());
     // Disposal method 4 is converted to ImageFrame::DisposeOverwritePrevious.
     EXPECT_EQ(ImageFrame::DisposeOverwritePrevious, decoder->frameBufferAtIndex(0)->disposalMethod());
     // Disposal method 5 is ignored.
     EXPECT_EQ(ImageFrame::DisposeNotSpecified, decoder->frameBufferAtIndex(1)->disposalMethod());
 }