Changed SkLightingShader API to take in a shader as color source

samplecode/SampleLighting.cpp

Index: samplecode/SampleLighting.cpp
diff --git a/samplecode/SampleLighting.cpp b/samplecode/SampleLighting.cpp
index 16b187408ac2051615cd97fb5f17b64909a23803..48d3f8a15ca51a804815b855c2da8a9766a19cf1 100755
--- a/samplecode/SampleLighting.cpp
+++ b/samplecode/SampleLighting.cpp
@@ -8,6 +8,7 @@
 #include "SampleCode.h"
 #include "Resources.h"
 
+#include "SkBitmapProcShader.h"
 #include "SkCanvas.h"
 #include "SkLightingShader.h"
 #include "SkNormalSource.h"
@@ -65,11 +66,13 @@ protected:
 
         sk_sp<SkLights> lights(create_lights(fLightAngle, fColorFactor));
         SkPaint paint;
+        sk_sp<SkShader> diffuseShader = SkBitmapProcShader::MakeBitmapShader(fDiffuseBitmap,
+                SkShader::kClamp_TileMode, SkShader::kClamp_TileMode, nullptr);
         sk_sp<SkNormalSource> normalSource = SkNormalSource::MakeMap(fNormalBitmap,
                                                                      SkVector::Make(1.0f, 0.0f),
                                                                      nullptr);
-        paint.setShader(SkLightingShader::Make(fDiffuseBitmap, std::move(lights), nullptr,
-                                               std::move(normalSource)));
+        paint.setShader(SkLightingShader::Make(std::move(diffuseShader), std::move(normalSource),
+                                               std::move(lights)));
         paint.setColor(SK_ColorBLACK);
 
         SkRect r = SkRect::MakeWH((SkScalar)fDiffuseBitmap.width(),