Add support for multiple frames in SkCodec

src/codec/SkCodecAnimation.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCodecAnimation_DEFINED
 #define SkCodecAnimation_DEFINED
 
+#include "SkCodec.h"
 #include "SkRect.h"
 
 class SkCodecAnimation {
 public:
     /**
      *  This specifies how the next frame is based on this frame.
      *
      *  Names are based on the GIF 89a spec.
      *
      *  The numbers correspond to values in a GIF.
@@ skipping 15 matching lines @@
 
         /**
          *  The next frame should be drawn on top of the previous frame - i.e.
          *  disregarding this one.
          *
          *  In a GIF, a value of 4 is also treated as RestorePrevious.
          */
         RestorePrevious_DisposalMethod  = 3,
     };
 
-    struct FrameInfo {
+    struct FrameInfo : public SkCodec::FrameInfo {
         DisposalMethod fDisposalMethod;
 
-        // The frame that this frame is drawn on top of, or
-        // SkCodec::kIndependentFrame.
-        size_t fRequiredFrame;
-
         // The subset of the bounds that this frame describes.
         SkIRect fFrameRect;
-
-        // How many 1/100 seconds to show this frame.
-        size_t fDuration;
     };
 private:
     SkCodecAnimation();
 };
 #endif // SkCodecAnimation_DEFINED