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 d7f446bb5766558eb2f4e5f91f2f99071ec7f740..ba4dc9af8995f2c9093889158a79b3a8990122d5 100644
--- a/src/codec/SkCodec_wbmp.cpp
+++ b/src/codec/SkCodec_wbmp.cpp
@@ -86,11 +86,8 @@ SkSwizzler* SkWbmpCodec::initializeSwizzler(const SkImageInfo& info,
                                       opts.fZeroInitialized);
 }
 
-SkCodec::Result SkWbmpCodec::readRow(uint8_t* row) {
-    if (this->stream()->read(row, fSrcRowBytes) != fSrcRowBytes) {
-        return kIncompleteInput;
-    }
-    return kSuccess;
+bool SkWbmpCodec::readRow(uint8_t* row) {
+    return this->stream()->read(row, fSrcRowBytes) == fSrcRowBytes;
 }
 
 SkWbmpCodec::SkWbmpCodec(const SkImageInfo& info, SkStream* stream)
@@ -109,7 +106,8 @@ SkCodec::Result SkWbmpCodec::onGetPixels(const SkImageInfo& info,
                                          size_t rowBytes,
                                          const Options& options,
                                          SkPMColor ctable[],
-                                         int* ctableCount) {
+                                         int* ctableCount,
+                                         int* rowsDecoded) {
     if (options.fSubset) {
         // Subsets are not supported.
         return kUnimplemented;
@@ -123,8 +121,8 @@ SkCodec::Result SkWbmpCodec::onGetPixels(const SkImageInfo& info,
     setup_color_table(info.colorType(), ctable, ctableCount);
 
     // Initialize the swizzler
-    SkAutoTDelete<SkSwizzler> swizzler(this->initializeSwizzler(info, ctable, options));
-    if (nullptr == swizzler.get()) {
+    fSwizzler.reset(this->initializeSwizzler(info, ctable, options));
+    if (nullptr == fSwizzler.get()) {
         return kInvalidConversion;
     }
 
@@ -133,11 +131,11 @@ SkCodec::Result SkWbmpCodec::onGetPixels(const SkImageInfo& info,
     SkAutoTMalloc<uint8_t> src(fSrcRowBytes);
     void* dstRow = dst;
     for (int y = 0; y < size.height(); ++y) {
-        Result rowResult = this->readRow(src.get());
-        if (kSuccess != rowResult) {
-            return rowResult;
+        if (!this->readRow(src.get())) {
+            *rowsDecoded = y;
+            return kIncompleteInput;
         }
-        swizzler->swizzle(dstRow, src.get());
+        fSwizzler->swizzle(dstRow, src.get());
         dstRow = SkTAddOffset<void>(dstRow, rowBytes);
     }
     return kSuccess;
@@ -158,17 +156,16 @@ SkCodec* SkWbmpCodec::NewFromStream(SkStream* stream) {
     return new SkWbmpCodec(info, streamDeleter.detach());
 }
 
-SkCodec::Result SkWbmpCodec::onGetScanlines(void* dst, int count, size_t dstRowBytes) {
+int SkWbmpCodec::onGetScanlines(void* dst, int count, size_t dstRowBytes) {
     void* dstRow = dst;
     for (int y = 0; y < count; ++y) {
-        Result rowResult = this->readRow(fSrcBuffer.get());
-        if (kSuccess != rowResult) {
-            return rowResult;
+        if (!this->readRow(fSrcBuffer.get())) {
+            return y;
         }
         fSwizzler->swizzle(dstRow, fSrcBuffer.get());
         dstRow = SkTAddOffset<void>(dstRow, dstRowBytes);
     }
-    return kSuccess;
+    return count;
 }
 
 SkCodec::Result SkWbmpCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
@@ -201,4 +198,3 @@ SkCodec::Result SkWbmpCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
 
     return kSuccess;
 }
-