use SkColorType instead of SkBitmap::Config in samplecode

BUG=skia:
R=reed@google.com

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/169063002

git-svn-id: http://skia.googlecode.com/svn/trunk@13473 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleRegion.cpp b/samplecode/SampleRegion.cpp
index c29f090..54858de 100644
--- a/samplecode/SampleRegion.cpp
+++ b/samplecode/SampleRegion.cpp
@@ -20,8 +20,7 @@
     int height = 100;
 
     SkBitmap bitmap;
-    bitmap.setConfig(SkBitmap::kA8_Config, width*2, height*2);
-    bitmap.allocPixels();
+    bitmap.allocPixels(SkImageInfo::MakeA8(width*2, height*2));
     bitmap.eraseColor(SK_ColorTRANSPARENT);
 
     SkScalar dx = 20;