Fill incomplete images in SkCodec parent class

tests/CodexTest.cpp

Index: tests/CodexTest.cpp
diff --git a/tests/CodexTest.cpp b/tests/CodexTest.cpp
index 041e71c67f46b12b356d7b864918b5f458a0696e..b5e503800f29be583f3d037f031654359f66616f 100644
--- a/tests/CodexTest.cpp
+++ b/tests/CodexTest.cpp
@@ -154,8 +154,8 @@ static void check(skiatest::Reporter* r,
         REPORTER_ASSERT(r, scanlineDecoder->start(info) == SkCodec::kSuccess);
 
         for (int y = 0; y < info.height(); y++) {
-            result = scanlineDecoder->getScanlines(bm.getAddr(0, y), 1, 0);
-            REPORTER_ASSERT(r, result == SkCodec::kSuccess);
+            const uint32_t lines = scanlineDecoder->getScanlines(bm.getAddr(0, y), 1, 0);
+            REPORTER_ASSERT(r, 1 == lines);
         }
         // verify that scanline decoding gives the same result.
         if (SkScanlineDecoder::kTopDown_SkScanlineOrder == scanlineDecoder->getScanlineOrder()) {