libwebp: update to 0.5.0

third_party/libwebp/enc/picture_tools.c

Index: third_party/libwebp/enc/picture_tools.c
diff --git a/third_party/libwebp/enc/picture_tools.c b/third_party/libwebp/enc/picture_tools.c
index 7c73646397b765e30f336c8db964ad565bf8afe3..bf97af84081a8173aaead759c8362897eb3eca9d 100644
--- a/third_party/libwebp/enc/picture_tools.c
+++ b/third_party/libwebp/enc/picture_tools.c
@@ -11,6 +11,8 @@
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
+#include <assert.h>
+
 #include "./vp8enci.h"
 #include "../dsp/yuv.h"
 
@@ -120,6 +122,24 @@ void WebPCleanupTransparentArea(WebPPicture* pic) {
 #undef SIZE
 #undef SIZE2
 
+void WebPCleanupTransparentAreaLossless(WebPPicture* const pic) {
+  int x, y, w, h;
+  uint32_t* argb;
+  assert(pic != NULL && pic->use_argb);
+  w = pic->width;
+  h = pic->height;
+  argb = pic->argb;
+
+  for (y = 0; y < h; ++y) {
+    for (x = 0; x < w; ++x) {
+      if ((argb[x] & 0xff000000) == 0) {
+        argb[x] = 0x00000000;
+      }
+    }
+    argb += pic->argb_stride;
+  }
+}
+
 //------------------------------------------------------------------------------
 // Blend color and remove transparency info