Always use a color table with 256 colors

src/codec/SkGifCodec.cpp

Index: src/codec/SkGifCodec.cpp
diff --git a/src/codec/SkGifCodec.cpp b/src/codec/SkGifCodec.cpp
index 1ede918657503a0e9d41321574b15eecd2bb4642..f507100810a8fbbd69b8b415e3bb856b5c3b188b 100644
--- a/src/codec/SkGifCodec.cpp
+++ b/src/codec/SkGifCodec.cpp
@@ -37,6 +37,7 @@
 #include "SkGifCodec.h"
 #include "SkStream.h"
 #include "SkSwizzler.h"
+#include "SkUtils.h"
 
 #include <algorithm>
 
@@ -143,9 +144,10 @@ void SkGifCodec::initializeColorTable(const SkImageInfo& dstInfo, size_t frameIn
     fCurrColorTable = fReader->getColorTable(dstInfo.colorType(), frameIndex);
     fCurrColorTableIsReal = fCurrColorTable;
     if (!fCurrColorTable) {
-        // This is possible for an empty frame. Create a dummy with one value (transparent).
-        SkPMColor color = SK_ColorTRANSPARENT;
-        fCurrColorTable.reset(new SkColorTable(&color, 1));
+        // This is possible for an empty frame. Create a dummy with all transparent.
+        SkPMColor colors[MAX_COLORS];
+        sk_memset32(colors, SK_ColorTRANSPARENT, MAX_COLORS);
+        fCurrColorTable.reset(new SkColorTable(colors, 256));
     }
 
     if (inputColorCount) {