Fill incomplete images in SkCodec parent class

src/codec/SkBmpMaskCodec.h

Index: src/codec/SkBmpMaskCodec.h
diff --git a/src/codec/SkBmpMaskCodec.h b/src/codec/SkBmpMaskCodec.h
index 1c44c7fb40975567069996a3e6f060930cf7abc2..1c1d1d8c116dd72d72cfbd45c048ffe5d7fda7a9 100644
--- a/src/codec/SkBmpMaskCodec.h
+++ b/src/codec/SkBmpMaskCodec.h
@@ -36,7 +36,7 @@ protected:
 
     Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
                        size_t dstRowBytes, const Options&, SkPMColor*,
-                       int*) override;
+                       int*, int*) override;
 
     SkCodec::Result prepareToDecode(const SkImageInfo& dstInfo,
             const SkCodec::Options& options, SkPMColor inputColorPtr[],
@@ -45,10 +45,13 @@ protected:
 private:
 
     bool initializeSwizzler(const SkImageInfo& dstInfo);
-    SkSampler* getSampler() override { return fMaskSwizzler; }
+    SkSampler* getSampler(bool createIfNecessary) override {
+        SkASSERT(fMaskSwizzler);
+        return fMaskSwizzler;
+    }
 
-    Result decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
-                      const Options& opts) override;
+    int decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
+            const Options& opts) override;
 
     SkAutoTDelete<SkMasks>              fMasks;        // owned
     SkAutoTDelete<SkMaskSwizzler>       fMaskSwizzler;