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/bench/benchmain.cpp b/bench/benchmain.cpp
index 80b7871..6f062e4 100644
--- a/bench/benchmain.cpp
+++ b/bench/benchmain.cpp
@@ -46,7 +46,7 @@
 
 static void erase(SkBitmap& bm) {
     if (bm.config() == SkBitmap::kA8_Config) {
-        bm.eraseColor(0);
+        bm.eraseColor(SK_ColorTRANSPARENT);
     } else {
         bm.eraseColor(SK_ColorWHITE);
     }