Use the upstream version of libwebp, v0.4.3.

src/images/SkImageDecoder_libwebp.cpp

 /*
  * Copyright 2010, The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
@@ skipping 15 matching lines @@
 // For more information on WebP image format, and libwebp library, see:
 //   http://code.google.com/speed/webp/
 //   http://www.webmproject.org/code/#libwebp_webp_image_decoder_library
 //   http://review.webmproject.org/gitweb?p=libwebp.git
 
 #include <stdio.h>
 extern "C" {
 // If moving libwebp out of skia source tree, path for webp headers must be
 // updated accordingly. Here, we enforce using local copy in webp sub-directory.
 #include "webp/decode.h"
+#include "webp/demux.h"
 #include "webp/encode.h"
 }
 
 // this enables timing code to report milliseconds for a decode
 //#define TIME_DECODE
 
 //////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////
 
 // Define VP8 I/O on top of Skia stream
@@ skipping 14 matching lines @@
         const size_t bytesRead = stream->read(dst, bytesToRead);
         if (0 == bytesRead) {
             SkASSERT(stream->isAtEnd());
             break;
         }
         bytesToRead -= bytesRead;
         totalBytesRead += bytesRead;
         SkASSERT(bytesToRead + totalBytesRead == WEBP_VP8_HEADER_SIZE);
     } while (!stream->isAtEnd() && bytesToRead > 0);
 
-    WebPBitstreamFeatures features;
-    VP8StatusCode status = WebPGetFeatures(buffer, totalBytesRead, &features);
-    if (VP8_STATUS_OK != status) {
-        return false; // Invalid WebP file.
+    WebPData demuxData = { buffer, totalBytesRead };
+    WebPDemuxState demuxState;
+    WebPDemuxer* demuxer = WebPDemuxPartial(&demuxData, &demuxState);
+    if (!demuxer) {
+        return false;
     }
-    *width = features.width;
-    *height = features.height;
-    *alpha = features.has_alpha;
+
+    SkAutoTCallVProc<WebPDemuxer, WebPDemuxDelete> autoDeleter(demuxer);
+    switch (demuxState) {
+        case WEBP_DEMUX_PARSE_ERROR:
+        case WEBP_DEMUX_PARSING_HEADER:
+            return false;
+        default:
+            // Header parsed.
+            break;
+    }
+
+    *width = WebPDemuxGetI(demuxer, WEBP_FF_CANVAS_WIDTH);
+    *height = WebPDemuxGetI(demuxer, WEBP_FF_CANVAS_HEIGHT);
+    uint32_t format_flags = WebPDemuxGetI(demuxer, WEBP_FF_FORMAT_FLAGS);
+    *alpha = SkToBool(format_flags & ALPHA_FLAG) ? 1 : 0;
 
     // sanity check for image size that's about to be decoded.
     {
         int64_t size = sk_64_mul(*width, *height);
         if (!sk_64_isS32(size)) {
             return false;
         }
         // now check that if we are 4-bytes per pixel, we also don't overflow
         if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) {
             return false;
@@ skipping 580 matching lines @@
     return SkImageDecoder::kUnknown_Format;
 }
 
 static SkImageEncoder* sk_libwebp_efactory(SkImageEncoder::Type t) {
       return (SkImageEncoder::kWEBP_Type == t) ? SkNEW(SkWEBPImageEncoder) : NULL;
 }
 
 static SkImageDecoder_DecodeReg gDReg(sk_libwebp_dfactory);
 static SkImageDecoder_FormatReg gFormatReg(get_format_webp);
 static SkImageEncoder_EncodeReg gEReg(sk_libwebp_efactory);