Abstracted diffuse color map out of SkLightingShaderImpl into a generic SkShader

src/core/SkLightingShader_NormalSource.cpp

Index: src/core/SkLightingShader_NormalSource.cpp
diff --git a/src/core/SkLightingShader_NormalSource.cpp b/src/core/SkLightingShader_NormalSource.cpp
index 15e3ecd789594f6bcbc46f3d81222f7941ebcfc3..2eeb709e00e7c9f83c9761260fc0a9424f5919ee 100644
--- a/src/core/SkLightingShader_NormalSource.cpp
+++ b/src/core/SkLightingShader_NormalSource.cpp
@@ -168,7 +168,6 @@ sk_sp<GrFragmentProcessor> NormalMapSourceImpl::asFragmentProcessor(
                                                      const SkMatrix *localMatrix,
                                                      SkFilterQuality filterQuality,
                                                      SkSourceGammaTreatment gammaTreatment) const {
-
     sk_sp<GrFragmentProcessor> bitmapFP = fBitmapShader->asFragmentProcessor(context, viewM,
             localMatrix, filterQuality, gammaTreatment);
 
@@ -278,7 +277,6 @@ void NormalMapSourceImpl::flatten(SkWriteBuffer& buf) const {
 
 sk_sp<SkLightingShader::NormalSource> SkLightingShader::NormalSource::MakeMap(
         const SkBitmap &normal, const SkVector &invNormRotation, const SkMatrix *normLocalM) {
-
     if (normal.isNull() || SkBitmapProcShader::BitmapIsTooBig(normal)) {
         return nullptr;
     }