use SkColorType instead of SkBitmap::Config in samplecode

samplecode/SampleShaderText.cpp

Index: samplecode/SampleShaderText.cpp
diff --git a/samplecode/SampleShaderText.cpp b/samplecode/SampleShaderText.cpp
index 6855824d3fb669946c032b68b2e025979e8ff659..c7048ab401c37c5a928c8206ffc9ab5e08167303 100644
--- a/samplecode/SampleShaderText.cpp
+++ b/samplecode/SampleShaderText.cpp
@@ -11,9 +11,8 @@
 #include "SkGradientShader.h"
 #include "SkUnitMappers.h"
 
-static void makebm(SkBitmap* bm, SkBitmap::Config config, int w, int h) {
-    bm->setConfig(config, w, h);
-    bm->allocPixels();
+static void makebm(SkBitmap* bm, int w, int h) {
+    bm->allocN32Pixels(w, h);
     bm->eraseColor(SK_ColorTRANSPARENT);
 
     SkCanvas    canvas(*bm);
@@ -39,7 +38,7 @@ static SkShader* MakeBitmapShader(SkShader::TileMode tx, SkShader::TileMode ty,
                            int w, int h) {
     static SkBitmap bmp;
     if (bmp.isNull()) {
-        makebm(&bmp, SkBitmap::kARGB_8888_Config, w/2, h/4);
+        makebm(&bmp, w/2, h/4);
     }
     return SkShader::CreateBitmapShader(bmp, tx, ty);
 }