use Make instead of Create to return a shared shader

src/utils/SkNinePatch.cpp

Index: src/utils/SkNinePatch.cpp
diff --git a/src/utils/SkNinePatch.cpp b/src/utils/SkNinePatch.cpp
index 5ee488e44b6a2cce5c0d48211749a1e81aaa6cd1..aeb65b1e2815d00a6bb992c30af9fd529cd5447a 100644
--- a/src/utils/SkNinePatch.cpp
+++ b/src/utils/SkNinePatch.cpp
@@ -236,14 +236,13 @@ void SkNinePatch::DrawMesh(SkCanvas* canvas, const SkRect& bounds,
     fillRow(verts, texs, bounds.fBottom, SkIntToScalar(bitmap.height()),
             bounds, xDivs, numXDivs, stretchX, bitmap.width());
 
-    SkShader* shader = SkShader::CreateBitmapShader(bitmap,
-                                                    SkShader::kClamp_TileMode,
-                                                    SkShader::kClamp_TileMode);
     SkPaint p;
     if (paint) {
         p = *paint;
     }
-    p.setShader(shader)->unref();
+    p.setShader(SkShader::MakeBitmapShader(bitmap,
+                                           SkShader::kClamp_TileMode,
+                                           SkShader::kClamp_TileMode));
     canvas->drawVertices(SkCanvas::kTriangles_VertexMode, vCount,
                          mesh.fVerts, mesh.fTexs, mesh.fColors, nullptr,
                          mesh.fIndices, indexCount, p);