Added PointLights to SkLights::Light

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2237493002

Review-Url: https://codereview.chromium.org/2237493002
diff --git a/gm/lightingshader2.cpp b/gm/lightingshader2.cpp
index 5e0d19b..70c9e29 100644
--- a/gm/lightingshader2.cpp
+++ b/gm/lightingshader2.cpp
@@ -43,9 +43,9 @@
         SkLights::Builder builder;
         const SkVector3 kLightFromUpperRight = SkVector3::Make(0.788f, 0.394f, 0.473f);
 
-        builder.add(SkLights::Light(SkColor3f::Make(1.0f, 1.0f, 1.0f),
-                                    kLightFromUpperRight));
-        builder.add(SkLights::Light(SkColor3f::Make(0.2f, 0.2f, 0.2f)));
+        builder.add(SkLights::Light::MakeDirectional(SkColor3f::Make(1.0f, 1.0f, 1.0f),
+                                                     kLightFromUpperRight));
+        builder.add(SkLights::Light::MakeAmbient(SkColor3f::Make(0.2f, 0.2f, 0.2f)));
         fLights = builder.finish();
 
         fRect = SkRect::MakeIWH(kTexSize, kTexSize);