use AsMode instead of deprecated IsMode



git-svn-id: http://skia.googlecode.com/svn/trunk@2705 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkBlitter.cpp b/src/core/SkBlitter.cpp
index 6bb0db4..307d51b 100644
--- a/src/core/SkBlitter.cpp
+++ b/src/core/SkBlitter.cpp
@@ -716,7 +716,7 @@
                                      SkBitmap::Config deviceConfig) {
     SkXfermode::Mode  mode;
 
-    if (SkXfermode::IsMode(xfer, &mode)) {
+    if (SkXfermode::AsMode(xfer, &mode)) {
         switch (mode) {
             case SkXfermode::kSrc_Mode:
                 if (just_solid_color(paint)) {