libwebp: update snapshot to v0.3.0-rc6

third_party/libwebp/webp/format_constants.h

Index: third_party/libwebp/webp/format_constants.h
diff --git a/third_party/libwebp/webp/format_constants.h b/third_party/libwebp/webp/format_constants.h
index 7ce498f67285f62e1e896742b53521b7c6c67bf8..8b3d6778ae0ce3b77d3fcfcff2d005a9538e577e 100644
--- a/third_party/libwebp/webp/format_constants.h
+++ b/third_party/libwebp/webp/format_constants.h
@@ -12,6 +12,9 @@
 #ifndef WEBP_WEBP_FORMAT_CONSTANTS_H_
 #define WEBP_WEBP_FORMAT_CONSTANTS_H_
 
+// Create fourcc of the chunk from the chunk tag characters.
+#define MKFOURCC(a, b, c, d) ((uint32_t)(a) | (b) << 8 | (c) << 16 | (d) << 24)
+
 // VP8 related constants.
 #define VP8_SIGNATURE 0x9d012a              // Signature in VP8 data.
 #define VP8_MAX_PARTITION0_SIZE (1 << 19)   // max size of mode partition
@@ -65,23 +68,16 @@ typedef enum {
 #define CHUNK_SIZE_BYTES   4     // Size needed to store chunk's size.
 #define CHUNK_HEADER_SIZE  8     // Size of a chunk header.
 #define RIFF_HEADER_SIZE   12    // Size of the RIFF header ("RIFFnnnnWEBP").
-#define FRAME_CHUNK_SIZE   15    // Size of a FRM chunk.
-#define LOOP_CHUNK_SIZE    2     // Size of a LOOP chunk.
-#define TILE_CHUNK_SIZE    6     // Size of a TILE chunk.
+#define ANMF_CHUNK_SIZE    16    // Size of an ANMF chunk.
+#define ANIM_CHUNK_SIZE    6     // Size of an ANIM chunk.
+#define FRGM_CHUNK_SIZE    6     // Size of a FRGM chunk.
 #define VP8X_CHUNK_SIZE    10    // Size of a VP8X chunk.
 
-#define TILING_FLAG_BIT    0x01  // Set if tiles are possibly used.
-#define ANIMATION_FLAG_BIT 0x02  // Set if some animation is expected
-#define ICC_FLAG_BIT       0x04  // Whether ICC is present or not.
-#define METADATA_FLAG_BIT  0x08  // Set if some META chunk is possibly present.
-#define ALPHA_FLAG_BIT     0x10  // Should be same as the ALPHA_FLAG in mux.h
-#define ROTATION_FLAG_BITS 0xe0  // all 3 bits for rotation + symmetry
-
 #define MAX_CANVAS_SIZE     (1 << 24)    // 24-bit max for VP8X width/height.
 #define MAX_IMAGE_AREA      (1ULL << 32) // 32-bit max for width x height.
 #define MAX_LOOP_COUNT      (1 << 16)    // maximum value for loop-count
 #define MAX_DURATION        (1 << 24)    // maximum duration
-#define MAX_POSITION_OFFSET (1 << 24)    // maximum frame/tile x/y offset
+#define MAX_POSITION_OFFSET (1 << 24)    // maximum frame/fragment x/y offset
 
 // Maximum chunk payload is such that adding the header and padding won't
 // overflow a uint32_t.