struct != class, even in a friend forward declare

git-svn-id: http://skia.googlecode.com/svn/trunk@9783 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkBitmap.h b/include/core/SkBitmap.h
index e03a46f..07d2ca5 100644
--- a/include/core/SkBitmap.h
+++ b/include/core/SkBitmap.h
@@ -691,7 +691,7 @@
     bool hasMipMap() const;
     void freeMipMap();
     
-    friend class SkBitmapProcState;
+    friend struct SkBitmapProcState;
 };
 
 class SkAutoLockPixels : public SkNoncopyable {