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 {