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/SampleRepeatTile.cpp b/samplecode/SampleRepeatTile.cpp
index 988345c..b352894 100644
--- a/samplecode/SampleRepeatTile.cpp
+++ b/samplecode/SampleRepeatTile.cpp
@@ -14,8 +14,7 @@
 static void make_bitmap(SkBitmap* bm) {
     const int W = 100;
     const int H = 100;
-    bm->setConfig(SkBitmap::kARGB_8888_Config, W, H);
-    bm->allocPixels();
+    bm->allocN32Pixels(W, H);
 
     SkPaint paint;
     SkCanvas canvas(*bm);