Update SampleApp to handle PNG encoded skps

https://codereview.appspot.com/6816105/



git-svn-id: http://skia.googlecode.com/svn/trunk@6347 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SamplePictFile.cpp b/samplecode/SamplePictFile.cpp
index 014ae93..ce80949 100644
--- a/samplecode/SamplePictFile.cpp
+++ b/samplecode/SamplePictFile.cpp
@@ -45,7 +45,8 @@
         } else {
             SkFILEStream stream(path);
             if (stream.isValid()) {
-                pic = SkNEW_ARGS(SkPicture, (&stream));
+                pic = SkNEW_ARGS(SkPicture, 
+                                 (&stream, NULL, &SkImageDecoder::DecodeStream));
             }
 
             if (false) { // re-record