[skottie] Guard against missing solid layer color property

Bug: skia:8281
Change-Id: I4a5d5e37d3b1bb0995c20ad138e8e234869ed760
Reviewed-on: https://skia-review.googlesource.com/148999
Commit-Queue: Florin Malita <fmalita@chromium.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Auto-Submit: Florin Malita <fmalita@chromium.org>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
diff --git a/modules/skottie/src/SkottieLayer.cpp b/modules/skottie/src/SkottieLayer.cpp
index a796683..1b00ffd 100644
--- a/modules/skottie/src/SkottieLayer.cpp
+++ b/modules/skottie/src/SkottieLayer.cpp
@@ -267,6 +267,7 @@
     const skjson::StringValue* hex_str = jlayer["sc"];
     uint32_t c;
     if (size.isEmpty() ||
+        !hex_str ||
         *hex_str->begin() != '#' ||
         !SkParse::FindHex(hex_str->begin() + 1, &c)) {
         LogJSON(jlayer, "!! Could not parse solid layer");