Add SkColorSpace to GrDrawContext

src/effects/SkAlphaThresholdFilter.cpp

Index: src/effects/SkAlphaThresholdFilter.cpp
diff --git a/src/effects/SkAlphaThresholdFilter.cpp b/src/effects/SkAlphaThresholdFilter.cpp
index 67ede53b4339cb5dad7a15868166c37f08085edd..f2b74300db94d17d4f92755cd9f2e945114cd360 100644
--- a/src/effects/SkAlphaThresholdFilter.cpp
+++ b/src/effects/SkAlphaThresholdFilter.cpp
@@ -104,7 +104,7 @@ sk_sp<GrTexture> SkAlphaThresholdFilterImpl::createMaskTexture(GrContext* contex
 
     sk_sp<GrDrawContext> drawContext(context->newDrawContext(SkBackingFit::kApprox,
                                                              bounds.width(), bounds.height(),
-                                                             config));
+                                                             config, nullptr));
     if (!drawContext) {
         return nullptr;
     }