SkColorTable locking serves no purpose anymore.

src/images/SkDecodingImageGenerator.cpp

Index: src/images/SkDecodingImageGenerator.cpp
diff --git a/src/images/SkDecodingImageGenerator.cpp b/src/images/SkDecodingImageGenerator.cpp
index cdee7c16764902c31d123d047ce42afa96474cfa..d5c2ba88186eeb547595e52cb890a16a5ff6abf4 100644
--- a/src/images/SkDecodingImageGenerator.cpp
+++ b/src/images/SkDecodingImageGenerator.cpp
@@ -199,8 +199,7 @@ bool DecodingImageGenerator::onGetPixels(const SkImageInfo& info,
             return false;
         }
         const int count = ctable->count();
-        memcpy(ctableEntries, ctable->lockColors(), count * sizeof(SkPMColor));
-        ctable->unlockColors();
+        memcpy(ctableEntries, ctable->readColors(), count * sizeof(SkPMColor));
         *ctableCount = count;
     }
     return true;