Revert of Make SkPngCodec decode progressively.

gm/factory.cpp

Index: gm/factory.cpp
diff --git a/gm/factory.cpp b/gm/factory.cpp
index 1468b55049996939f95903dbe219aa15ec615ae8..831cff0b9f90f693b6686288bc51ec77611575bb 100644
--- a/gm/factory.cpp
+++ b/gm/factory.cpp
@@ -35,8 +35,9 @@
             // bitmap is unlocked.
             SkAutoTUnref<SkDiscardableMemoryPool> pool(
                 SkDiscardableMemoryPool::Create(1));
-            SkDEPRECATED_InstallDiscardablePixelRef(SkImageGenerator::NewFromEncoded(data),
-                                                    nullptr, &fBitmap, pool);
+            SkAssertResult(SkDEPRECATED_InstallDiscardablePixelRef(
+                                                        SkImageGenerator::NewFromEncoded(data),
+                                                        nullptr, &fBitmap, pool));
         }
     }