libwebp: update to 0.5.0

third_party/libwebp/enc/delta_palettization.h

Index: third_party/libwebp/enc/delta_palettization.h
diff --git a/third_party/libwebp/enc/delta_palettization.h b/third_party/libwebp/enc/delta_palettization.h
new file mode 100644
index 0000000000000000000000000000000000000000..e41c0c5ab56095e93d2ed77f526a858e261c21de
--- /dev/null
+++ b/third_party/libwebp/enc/delta_palettization.h
@@ -0,0 +1,25 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Author: Mislav Bradac (mislavm@google.com)
+//
+
+#ifndef WEBP_ENC_DELTA_PALETTIZATION_H_
+#define WEBP_ENC_DELTA_PALETTIZATION_H_
+
+#include "../webp/encode.h"
+#include "../enc/vp8li.h"
+
+// Replaces enc->argb_[] input by a palettizable approximation of it,
+// and generates optimal enc->palette_[].
+// This function can revert enc->use_palette_ / enc->use_predict_ flag
+// if delta-palettization is not producing expected saving.
+WebPEncodingError WebPSearchOptimalDeltaPalette(VP8LEncoder* const enc);
+
+#endif  // WEBP_ENC_DELTA_PALETTIZATION_H_