Fix bug in SkGifCodec / Switch SkImageDec tests to use Codec

tests/CachedDecodingPixelRefTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkDiscardableMemoryPool.h"
-#include "SkImageDecoder.h"
+#include "SkImage.h"
+#include "SkImageEncoder.h"
 #include "SkImageGeneratorPriv.h"
 #include "SkResourceCache.h"
 #include "SkStream.h"
 #include "SkUtils.h"
 
 #include "Test.h"
 
 /**
  * Fill this bitmap with some color.
  */
@@ skipping 315 matching lines @@
             if (TestImageGenerator::kSucceedGetPixels_TestType == test) {
                 REPORTER_ASSERT(
                     r, TestImageGenerator::Color() == bitmap.getColor(0, 0));
             }
             else {
                 REPORTER_ASSERT(r, kDefaultColor == bitmap.getColor(0, 0));
             }
         }
     }
 }