promote SkImage::AlphaType to SkAlphaType

tools/skhello.cpp

Index: tools/skhello.cpp
diff --git a/tools/skhello.cpp b/tools/skhello.cpp
index bd3174252e8f228731926c9189dc04f98b7a166e..d30849bcfb4d987d3de8e097bfe26db8ef0fcfb2 100644
--- a/tools/skhello.cpp
+++ b/tools/skhello.cpp
@@ -30,10 +30,7 @@ static void doDraw(SkCanvas* canvas, const SkPaint& paint, const char text[]) {
 
 static bool do_surface(int w, int h, const char path[], const char text[],
                        const SkPaint& paint) {
-    SkImage::Info info = {
-        w, h, SkImage::kPMColor_ColorType, SkImage::kPremul_AlphaType
-    };
-    SkAutoTUnref<SkSurface> surface(SkSurface::NewRaster(info));
+    SkAutoTUnref<SkSurface> surface(SkSurface::NewRasterPMColor(w, h));
     doDraw(surface->getCanvas(), paint, text);
 
     SkAutoTUnref<SkImage> image(surface->newImageSnapshot());