Update files to use SK_BUILD_FOR_ANDROID.

This CL also removes any unecessary references to
the ANDROID definition.
Review URL: http://codereview.appspot.com/5354049

git-svn-id: http://skia.googlecode.com/svn/trunk@2629 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/SkPorterDuff.cpp b/src/effects/SkPorterDuff.cpp
index 515a3d4..8acb345 100644
--- a/src/effects/SkPorterDuff.cpp
+++ b/src/effects/SkPorterDuff.cpp
@@ -39,7 +39,7 @@
     MAKE_PAIR(Multiply),
     MAKE_PAIR(Screen),
     { SkPorterDuff::kAdd_Mode, SkXfermode::kPlus_Mode },
-#ifdef ANDROID
+#ifdef SK_BUILD_FOR_ANDROID
     MAKE_PAIR(Overlay),
 #endif
 };