Update libwebp and resume testing scaled webp

dm/DM.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
@@ skipping 284 matching lines @@
             colorTypes[1] = CodecSrc::kIndex8_Always_DstColorType;
             numColorTypes = 2;
             break;
         default:
             colorTypes[0] = CodecSrc::kGetFromCanvas_DstColorType;
             numColorTypes = 1;
             break;
     }
 
     for (float scale : nativeScales) {
-        if (scale != 1.0f && (path.endsWith(".webp") || path.endsWith(".WEBP"))) {
-            // FIXME: skbug.com/4038 Scaling webp seems to leave some pixels uninitialized/
-            // compute their colors based on uninitialized values.
-            continue;
-        }
-
         for (CodecSrc::Mode mode : nativeModes) {
             for (uint32_t i = 0; i < numColorTypes; i++) {
                 push_codec_src(path, mode, colorTypes[i], scale);
             }
         }
     }
 
     if (path.endsWith(".ico") || path.endsWith(".ICO")) {
         // FIXME: skbug.com/4404: ICO does not have the ability to decode scanlines, so we cannot
         // use SkScaledCodec with it.
@@ skipping 793 matching lines @@
     #endif  // SK_PDF_IMAGE_STATS
     return 0;
 }
 
 #if !defined(SK_BUILD_FOR_IOS)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif