Defining new color constat for transparent color
Review URL: https://codereview.appspot.com/6901044

git-svn-id: http://skia.googlecode.com/svn/trunk@6696 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleShaderText.cpp b/samplecode/SampleShaderText.cpp
index cada977..a83b099 100644
--- a/samplecode/SampleShaderText.cpp
+++ b/samplecode/SampleShaderText.cpp
@@ -14,7 +14,7 @@
 static void makebm(SkBitmap* bm, SkBitmap::Config config, int w, int h) {
     bm->setConfig(config, w, h);
     bm->allocPixels();
-    bm->eraseColor(0);
+    bm->eraseColor(SK_ColorTRANSPARENT);
 
     SkCanvas    canvas(*bm);
     SkScalar s = SkIntToScalar(w < h ? w : h);