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 d8ec87d53271ed26a15f4d0c9e06ac60405e7759..1371e441d4894a9d1060012e54fab0aa236f117c 100644
--- a/include/core/SkLights.h
+++ b/include/core/SkLights.h
@@ -22,7 +22,6 @@ public:
     class Light {
     public:
         enum LightType {
-            kAmbient_LightType,       // only 'fColor' is used
             kDirectional_LightType,
             kPoint_LightType
         };
@@ -43,10 +42,6 @@ public:
             , 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) {
             Light light(kDirectional_LightType, color, dir);
             if (!light.fDirOrPos.normalize()) {
@@ -123,17 +118,17 @@ public:
         sk_sp<SkImage> fShadowMap;
 
         Light(LightType type, const SkColor3f& color,
-              const SkVector3& dir, SkScalar intensity = 0.0f) {
+              const SkVector3& dirOrPos, SkScalar intensity = 0.0f) {
             fType = type;
             fColor = color;
-            fDirOrPos = dir;
+            fDirOrPos = dirOrPos;
             fIntensity = intensity;
         }
     };
 
     class Builder {
     public:
-        Builder() : fLights(new SkLights) { }
+        Builder() : fLights(new SkLights) {}
 
         void add(const Light& light) {
             if (fLights) {
@@ -147,6 +142,12 @@ public:
             }
         }
 
+        void setAmbientLightColor(const SkColor3f& color) {
+            if (fLights) {
+                fLights->fAmbientLightColor = color;
+            }
+        }
+
         sk_sp<SkLights> finish() {
             return std::move(fLights);
         }
@@ -167,13 +168,20 @@ public:
         return fLights[index];
     }
 
+    const SkColor3f& ambientLightColor() const {
+        return fAmbientLightColor;
+    }
+
     static sk_sp<SkLights> MakeFromBuffer(SkReadBuffer& buf);
 
     void flatten(SkWriteBuffer& buf) const;
 
 private:
-    SkLights() {}
+    SkLights() {
+        fAmbientLightColor.set(0.0f, 0.0f, 0.0f);
+    }
     SkTArray<Light> fLights;
+    SkColor3f fAmbientLightColor;
     typedef SkRefCnt INHERITED;
 };