SkLS accepts nullptr for pointer args, handles alpha accurately, has new GM

tests/SerializationTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Resources.h"
 #include "SkAnnotationKeys.h"
 #include "SkBitmapProcShader.h"
@@ skipping 569 matching lines @@
         SkBitmap normals;
         normals.allocN32Pixels(kTexSize, kTexSize);
 
         sk_tool_utils::create_frustum_normal_map(&normals, SkIRect::MakeWH(kTexSize, kTexSize));
         sk_sp<SkShader> normalMap = SkMakeBitmapShader(normals, SkShader::kClamp_TileMode,
                                                        SkShader::kClamp_TileMode, &matrix, nullptr);
         sk_sp<SkNormalSource> normalSource = SkNormalSource::MakeFromNormalMap(std::move(normalMap),
                                                                                ctm);
         sk_sp<SkShader> diffuseShader = SkMakeBitmapShader(diffuse, SkShader::kClamp_TileMode,
                 SkShader::kClamp_TileMode, &matrix, nullptr);
-        sk_sp<SkShader> lightingShader = SkLightingShader::Make(std::move(diffuseShader),
-                                                                std::move(normalSource),
+
+        sk_sp<SkShader> lightingShader = SkLightingShader::Make(diffuseShader,
+                                                                normalSource,
                                                                 fLights);
+        SkAutoTUnref<SkShader>(TestFlattenableSerialization(lightingShader.get(), true, reporter));
 
+        lightingShader = SkLightingShader::Make(std::move(diffuseShader),
+                                                nullptr,
+                                                fLights);
         SkAutoTUnref<SkShader>(TestFlattenableSerialization(lightingShader.get(), true, reporter));
-        // TODO test equality?
 
+        lightingShader = SkLightingShader::Make(nullptr,
+                                                std::move(normalSource),
+                                                fLights);
+        SkAutoTUnref<SkShader>(TestFlattenableSerialization(lightingShader.get(), true, reporter));
+
+        lightingShader = SkLightingShader::Make(nullptr,
+                                                nullptr,
+                                                fLights);
+        SkAutoTUnref<SkShader>(TestFlattenableSerialization(lightingShader.get(), true, reporter));
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 #include "SkAnnotation.h"
 
 static sk_sp<SkPicture> copy_picture_via_serialization(SkPicture* src) {
     SkDynamicMemoryWStream wstream;
     src->serialize(&wstream);
     SkAutoTDelete<SkStreamAsset> rstream(wstream.detachAsStream());
@@ skipping 63 matching lines @@
         { r1, SkAnnotationKeys::Define_Named_Dest_Key(),    d1 },
         { r2, SkAnnotationKeys::Link_Named_Dest_Key(),      d2 },
     };
 
     sk_sp<SkPicture> pict0(recorder.finishRecordingAsPicture());
     sk_sp<SkPicture> pict1(copy_picture_via_serialization(pict0.get()));
 
     TestAnnotationCanvas canvas(reporter, recs, SK_ARRAY_COUNT(recs));
     canvas.drawPicture(pict1);
 }