libwebp: upstream animation cherry-picks

third_party/libwebp/webp/demux.h

Index: third_party/libwebp/webp/demux.h
diff --git a/third_party/libwebp/webp/demux.h b/third_party/libwebp/webp/demux.h
index c7cd5d66dbb0405e649bd6972205e99cf9251f79..894ff4ef247e1842c54756fe92ee2bd52f688c2c 100644
--- a/third_party/libwebp/webp/demux.h
+++ b/third_party/libwebp/webp/demux.h
@@ -53,7 +53,7 @@
 extern "C" {
 #endif
 
-#define WEBP_DEMUX_ABI_VERSION 0x0100    // MAJOR(8b) + MINOR(8b)
+#define WEBP_DEMUX_ABI_VERSION 0x0101    // MAJOR(8b) + MINOR(8b)
 
 // Note: forward declaring enumerations is not allowed in (strict) C and C++,
 // the types are left here for reference.
@@ -136,8 +136,10 @@ struct WebPIterator {
                   // may still be decoded with the WebP incremental decoder.
   WebPData fragment;  // The frame or fragment given by 'frame_num' and
                       // 'fragment_num'.
+  int has_alpha;      // True if the frame or fragment contains transparency.
+  WebPMuxAnimBlend blend_method;  // Blend operation for the frame.
 
-  uint32_t pad[4];         // padding for later use.
+  uint32_t pad[2];         // padding for later use.
   void* private_;          // for internal use only.
 };