Make SkDevice::onReadPixels take a const& rather than const*



git-svn-id: http://skia.googlecode.com/svn/trunk@2587 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/pdf/SkPDFDevice.h b/include/pdf/SkPDFDevice.h
index b25e39a..1e4db86 100644
--- a/include/pdf/SkPDFDevice.h
+++ b/include/pdf/SkPDFDevice.h
@@ -158,7 +158,7 @@
     }
     
 protected:
-    virtual bool onReadPixels(const SkBitmap* bitmap,
+    virtual bool onReadPixels(const SkBitmap& bitmap,
                               int x, int y) SK_OVERRIDE {
         return false;
     }