Another iOS fix for SampleApp.

R=caryclark@google.com

Author: jvanverth@google.com

Review URL: https://codereview.chromium.org/353683003
diff --git a/src/utils/ios/SkImageDecoder_iOS.mm b/src/utils/ios/SkImageDecoder_iOS.mm
index 5e4261f..021fa25 100755
--- a/src/utils/ios/SkImageDecoder_iOS.mm
+++ b/src/utils/ios/SkImageDecoder_iOS.mm
@@ -29,8 +29,7 @@
     
     const int width = uimage.size.width;
     const int height = uimage.size.height;
-    SkColorType ct = SkBitmapConfigToColorType(SkBitmap::kARGB_8888_Config);
-    bm->setInfo(SkImageInfo::Make(width, height, ct, kPremul_SkAlphaType), 0);
+    bm->setInfo(SkImageInfo::MakeN32(width, height, kPremul_SkAlphaType), 0);
     if (SkImageDecoder::kDecodeBounds_Mode == mode) {
         return true;
     }