Fill incomplete images in SkCodec parent class

src/codec/SkCodec_wbmp.cpp

Index: src/codec/SkCodec_wbmp.cpp
diff --git a/src/codec/SkCodec_wbmp.cpp b/src/codec/SkCodec_wbmp.cpp
index 22f2bacce0d22f4fb4246a7f8c06338c1f09be17..61f64219c1af8ed1d85fb34823934e0ea15389f5 100644
--- a/src/codec/SkCodec_wbmp.cpp
+++ b/src/codec/SkCodec_wbmp.cpp
@@ -107,7 +107,8 @@ SkCodec::Result SkWbmpCodec::onGetPixels(const SkImageInfo& info,
                                          size_t rowBytes,
                                          const Options& options,
                                          SkPMColor ctable[],
-                                         int* ctableCount) {
+                                         int* ctableCount,
+                                         int* incompleteScanlines) {
     if (!this->rewindIfNeeded()) {
         return kCouldNotRewind;
     }
@@ -140,6 +141,7 @@ SkCodec::Result SkWbmpCodec::onGetPixels(const SkImageInfo& info,
     for (int y = 0; y < size.height(); ++y) {
         Result rowResult = this->readRow(src.get());
         if (kSuccess != rowResult) {
+            *incompleteScanlines = size.height() - y;
             return rowResult;
         }
         swizzler->swizzle(dstRow, src.get());
@@ -169,24 +171,24 @@ public:
      * Takes ownership of all pointer paramters.
      */
     SkWbmpScanlineDecoder(SkWbmpCodec* codec)
-        : INHERITED(codec->getInfo())
+        : INHERITED(codec, codec->getInfo())
         , fCodec(codec)
         , fColorTable(nullptr)
         , fSwizzler(nullptr)
         , fSrcBuffer(codec->fSrcRowBytes)
     {}
 
-    SkCodec::Result onGetScanlines(void* dst, int count, size_t dstRowBytes) override {
+    uint32_t onGetScanlines(void* dst, int count, size_t dstRowBytes) override {
         void* dstRow = dst;
         for (int y = 0; y < count; ++y) {
             SkCodec::Result rowResult = fCodec->readRow(fSrcBuffer.get());
             if (SkCodec::kSuccess != rowResult) {
-                return rowResult;
+                return y;
             }
             fSwizzler->swizzle(dstRow, fSrcBuffer.get());
             dstRow = SkTAddOffset<void>(dstRow, dstRowBytes);
         }
-        return SkCodec::kSuccess;
+        return count;
     }
 
     SkCodec::Result onStart(const SkImageInfo& dstInfo,
@@ -232,7 +234,7 @@ public:
     }
 
 private:
-    SkAutoTDelete<SkWbmpCodec>   fCodec;
+    SkWbmpCodec*                 fCodec; // Owned by parent class
     SkAutoTUnref<SkColorTable>   fColorTable;
     SkAutoTDelete<SkSwizzler>    fSwizzler;
     SkAutoTMalloc<uint8_t>       fSrcBuffer;