Use the upstream version of libwebp, v0.4.3.

src/images/SkImageDecoder_libwebp.cpp

Index: src/images/SkImageDecoder_libwebp.cpp
diff --git a/src/images/SkImageDecoder_libwebp.cpp b/src/images/SkImageDecoder_libwebp.cpp
index a7c9610d07ad0d7313406dd79d9a644cede5b22f..5b5e73e1a0b91bb5a34fbf95794ee820f9d9a11e 100644
--- a/src/images/SkImageDecoder_libwebp.cpp
+++ b/src/images/SkImageDecoder_libwebp.cpp
@@ -33,6 +33,7 @@ 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"
 }
 
@@ -67,14 +68,27 @@ static bool webp_parse_header(SkStream* stream, int* width, int* height, int* al
         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.
     {