Abstracted diffuse color map out of SkLightingShaderImpl into a generic SkShader

src/core/SkNormalSource.cpp

Index: src/core/SkNormalSource.cpp
diff --git a/src/core/SkNormalSource.cpp b/src/core/SkNormalSource.cpp
index cadf47e29ce5b57dfa96acf13136541a6515d4dd..9787e47584ba9ecb95a06ac3613ceccac1d54921 100644
--- a/src/core/SkNormalSource.cpp
+++ b/src/core/SkNormalSource.cpp
@@ -169,7 +169,6 @@ sk_sp<GrFragmentProcessor> NormalMapSourceImpl::asFragmentProcessor(
                                                      const SkMatrix *localMatrix,
                                                      SkFilterQuality filterQuality,
                                                      SkSourceGammaTreatment gammaTreatment) const {
-
     sk_sp<GrFragmentProcessor> bitmapFP = fBitmapShader->asFragmentProcessor(context, viewM,
             localMatrix, filterQuality, gammaTreatment);
 
@@ -279,7 +278,6 @@ void NormalMapSourceImpl::flatten(SkWriteBuffer& buf) const {
 
 sk_sp<SkNormalSource> SkNormalSource::MakeMap(
         const SkBitmap &normal, const SkVector &invNormRotation, const SkMatrix *normLocalM) {
-
     if (normal.isNull() || SkBitmapProcShader::BitmapIsTooBig(normal)) {
         return nullptr;
     }