Revert of Moved ambient lights out of SkLight's light array

include/core/SkLights.h

Index: include/core/SkLights.h
diff --git a/include/core/SkLights.h b/include/core/SkLights.h
index 1371e441d4894a9d1060012e54fab0aa236f117c..d8ec87d53271ed26a15f4d0c9e06ac60405e7759 100644
--- a/include/core/SkLights.h
+++ b/include/core/SkLights.h
@@ -22,6 +22,7 @@
     class Light {
     public:
         enum LightType {
+            kAmbient_LightType,       // only 'fColor' is used
             kDirectional_LightType,
             kPoint_LightType
         };
@@ -40,6 +41,10 @@
             , fDirOrPos(other.fDirOrPos)
             , fIntensity(other.fIntensity)
             , fShadowMap(std::move(other.fShadowMap)) {
+        }
+
+        static Light MakeAmbient(const SkColor3f& color) {
+            return Light(kAmbient_LightType, color, SkVector3::Make(0.0f, 0.0f, 1.0f));
         }
 
         static Light MakeDirectional(const SkColor3f& color, const SkVector3& dir) {
@@ -118,17 +123,17 @@
         sk_sp<SkImage> fShadowMap;
 
         Light(LightType type, const SkColor3f& color,
-              const SkVector3& dirOrPos, SkScalar intensity = 0.0f) {
+              const SkVector3& dir, SkScalar intensity = 0.0f) {
             fType = type;
             fColor = color;
-            fDirOrPos = dirOrPos;
+            fDirOrPos = dir;
             fIntensity = intensity;
         }
     };
 
     class Builder {
     public:
-        Builder() : fLights(new SkLights) {}
+        Builder() : fLights(new SkLights) { }
 
         void add(const Light& light) {
             if (fLights) {
@@ -139,12 +144,6 @@
         void add(Light&& light) {
             if (fLights) {
                 fLights->fLights.push_back(std::move(light));
-            }
-        }
-
-        void setAmbientLightColor(const SkColor3f& color) {
-            if (fLights) {
-                fLights->fAmbientLightColor = color;
             }
         }
 
@@ -168,20 +167,13 @@
         return fLights[index];
     }
 
-    const SkColor3f& ambientLightColor() const {
-        return fAmbientLightColor;
-    }
-
     static sk_sp<SkLights> MakeFromBuffer(SkReadBuffer& buf);
 
     void flatten(SkWriteBuffer& buf) const;
 
 private:
-    SkLights() {
-        fAmbientLightColor.set(0.0f, 0.0f, 0.0f);
-    }
+    SkLights() {}
     SkTArray<Light> fLights;
-    SkColor3f fAmbientLightColor;
     typedef SkRefCnt INHERITED;
 };