Added API for Bevel NormalSource.

gm/lightingshader.cpp

Index: gm/lightingshader.cpp
diff --git a/gm/lightingshader.cpp b/gm/lightingshader.cpp
index 2cf4a953d800b78c0577a57f48daa020168ee698..e2f616fa67d646d6a5d9029384388b66b7f2db0d 100644
--- a/gm/lightingshader.cpp
+++ b/gm/lightingshader.cpp
@@ -112,6 +112,25 @@ protected:
         canvas->drawRect(r, paint);
     }
 
+    void drawBevelRect(SkCanvas* canvas, const SkRect& r) {
+
+        SkRect bitmapBounds = SkRect::MakeIWH(fDiffuse.width(), fDiffuse.height());
+
+        SkMatrix matrix;
+        matrix.setRectToRect(bitmapBounds, r, SkMatrix::kFill_ScaleToFit);
+
+        SkPaint paint;
+        auto diffuseShader = SkBitmapProcShader::MakeBitmapShader(fDiffuse,
+                SkShader::kClamp_TileMode, SkShader::kClamp_TileMode, &matrix);
+        auto normalSource = SkNormalSource::MakeBevel(SkNormalSource::BevelType::kLinear,
+                                                      0.15f * SkIntToScalar(kTexSize),
+                                                      0.2f * SkIntToScalar(kTexSize));
+        paint.setShader(SkLightingShader::Make(std::move(diffuseShader), std::move(normalSource),
+                                               fLights));
+
+        canvas->drawRect(r, paint);
+    }
+
     void onDraw(SkCanvas* canvas) override {
         SkMatrix m;
         SkRect r;
@@ -136,7 +155,7 @@ protected:
             m.setRotate(45.0f, r.centerX(), r.centerY());
             m.postTranslate(0.0f, kGMSize/2.0f - kTexSize/2.0f);
             canvas->setMatrix(m);
-            this->drawRect(canvas, r, kFrustum_NormalMap);
+            this->drawBevelRect(canvas, r);
             canvas->restore();
         }