promote SkImage::AlphaType to SkAlphaType

src/image/SkSurface_Picture.cpp

Index: src/image/SkSurface_Picture.cpp
diff --git a/src/image/SkSurface_Picture.cpp b/src/image/SkSurface_Picture.cpp
index 79812c4a61c43b5fe2d3fb3699ac262a62a74a5a..915530c8dc05f1760a1c7acdabb40e4bc664cb77 100644
--- a/src/image/SkSurface_Picture.cpp
+++ b/src/image/SkSurface_Picture.cpp
@@ -62,7 +62,7 @@ SkImage* SkSurface_Picture::onNewImageSnapshot() {
         SkImage::Info info;
         info.fWidth = info.fHeight = 0;
         info.fColorType = SkImage::kPMColor_ColorType;
-        info.fAlphaType = SkImage::kOpaque_AlphaType;
+        info.fAlphaType = kOpaque_SkAlphaType;
         return SkImage::NewRasterCopy(info, NULL, 0);
     }
 }