move setshader to sk_sp, re-using SK_SUPPORT_LEGACY_CREATESHADER_PTR

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1829303002

Review URL: https://codereview.chromium.org/1829303002
diff --git a/samplecode/SampleCamera.cpp b/samplecode/SampleCamera.cpp
index ed6cc52..85b854e 100644
--- a/samplecode/SampleCamera.cpp
+++ b/samplecode/SampleCamera.cpp
@@ -20,7 +20,7 @@
 #include "SkRandom.h"
 
 class CameraView : public SampleView {
-    SkTDArray<SkShader*> fShaders;
+    SkTArray<sk_sp<SkShader>> fShaders;
     int     fShaderIndex;
     bool    fFrontFace;
 public:
@@ -39,11 +39,10 @@
                 SkMatrix matrix;
                 matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
 
-                SkShader* s = SkShader::MakeBitmapShader(bm,
+                fShaders.push_back(SkShader::MakeBitmapShader(bm,
                                                            SkShader::kClamp_TileMode,
                                                            SkShader::kClamp_TileMode,
-                                                           &matrix).release();
-                *fShaders.append() = s;
+                                                           &matrix));
             } else {
                 break;
             }
@@ -51,10 +50,6 @@
         this->setBGColor(0xFFDDDDDD);
     }
 
-    virtual ~CameraView() {
-        fShaders.unrefAll();
-    }
-
 protected:
     // overrides from SkEventSink
     bool onQuery(SkEvent* evt) override {
diff --git a/samplecode/SampleEmboss.cpp b/samplecode/SampleEmboss.cpp
index 6e33e05..215a1e0 100644
--- a/samplecode/SampleEmboss.cpp
+++ b/samplecode/SampleEmboss.cpp
@@ -9,7 +9,6 @@
 #include "SkBlurMask.h"
 #include "SkView.h"
 #include "SkCanvas.h"
-#include "SkColorShader.h"
 #include "SkEmbossMaskFilter.h"
 #include "SkGradientShader.h"
 #include "SkGraphics.h"
@@ -53,7 +52,7 @@
         paint.setStrokeWidth(SkIntToScalar(10));
         paint.setMaskFilter(SkEmbossMaskFilter::Create(
             SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(4)), fLight))->unref();
-        paint.setShader(new SkColorShader(SK_ColorBLUE))->unref();
+        paint.setShader(SkShader::MakeColorShader(SK_ColorBLUE));
         paint.setDither(true);
 
         canvas->drawCircle(SkIntToScalar(50), SkIntToScalar(50),
diff --git a/samplecode/SampleFilterFuzz.cpp b/samplecode/SampleFilterFuzz.cpp
index 82934ea..dd72d12 100644
--- a/samplecode/SampleFilterFuzz.cpp
+++ b/samplecode/SampleFilterFuzz.cpp
@@ -648,10 +648,10 @@
         break;
     case NOISE:
     {
-        SkAutoTUnref<SkShader> shader((R(2) == 1) ?
-            SkPerlinNoiseShader::CreateFractalNoise(
+        sk_sp<SkShader> shader((R(2) == 1) ?
+            SkPerlinNoiseShader::MakeFractalNoise(
                 make_scalar(true), make_scalar(true), R(10.0f), make_scalar()) :
-            SkPerlinNoiseShader::CreateTurbulence(
+            SkPerlinNoiseShader::MakeTurbulence(
                 make_scalar(true), make_scalar(true), R(10.0f), make_scalar()));
         SkPaint paint;
         paint.setShader(shader);
diff --git a/samplecode/SampleLighting.cpp b/samplecode/SampleLighting.cpp
index fa88e3e..1da888f 100755
--- a/samplecode/SampleLighting.cpp
+++ b/samplecode/SampleLighting.cpp
@@ -31,11 +31,10 @@
 
 class LightingView : public SampleView {
 public:
-    SkAutoTUnref<SkShader> fShader;
-    SkBitmap               fDiffuseBitmap;
-    SkBitmap               fNormalBitmap;
-    SkScalar               fLightAngle;
-    SkScalar               fColorFactor;
+    SkBitmap        fDiffuseBitmap;
+    SkBitmap        fNormalBitmap;
+    SkScalar        fLightAngle;
+    SkScalar        fColorFactor;
 
     LightingView() {
         SkString diffusePath = GetResourcePath("brickwork-texture.jpg");
@@ -45,16 +44,8 @@
 
         fLightAngle = 0.0f;
         fColorFactor = 0.0f;
-
-        SkAutoTUnref<const SkLightingShader::Lights> lights(create_lights(fLightAngle, 1.0f));
-
-        fShader.reset(SkLightingShader::Create(fDiffuseBitmap, fNormalBitmap,
-                                               lights, SkVector::Make(1.0f, 0.0f),
-                                               nullptr, nullptr));
     }
 
-    virtual ~LightingView() {}
-
 protected:
     // overrides from SkEventSink
     bool onQuery(SkEvent* evt) override {
@@ -74,13 +65,10 @@
 
         SkAutoTUnref<const SkLightingShader::Lights> lights(create_lights(fLightAngle,
                                                                           fColorFactor));
-
-        fShader.reset(SkLightingShader::Create(fDiffuseBitmap, fNormalBitmap,
+        SkPaint paint;
+        paint.setShader(SkLightingShader::Make(fDiffuseBitmap, fNormalBitmap,
                                                lights, SkVector::Make(1.0f, 0.0f),
                                                nullptr, nullptr));
-
-        SkPaint paint;
-        paint.setShader(fShader);
         paint.setColor(SK_ColorBLACK);
 
         SkRect r = SkRect::MakeWH((SkScalar)fDiffuseBitmap.width(),