Scanline decoding for bmp

src/codec/SkBmpStandardCodec.h

Index: src/codec/SkBmpStandardCodec.h
diff --git a/src/codec/SkBmpStandardCodec.h b/src/codec/SkBmpStandardCodec.h
index 45450e65918b95c5d5222ec36cb3ddba9f28edfa..1cbefccb21f57456d6e0ca192c556a05b68b1f0e 100644
--- a/src/codec/SkBmpStandardCodec.h
+++ b/src/codec/SkBmpStandardCodec.h
@@ -36,8 +36,9 @@ public:
      * @param rowOrder indicates whether rows are ordered top-down or bottom-up
      */
     SkBmpStandardCodec(const SkImageInfo& srcInfo, SkStream* stream,
-               uint16_t bitsPerPixel, uint32_t numColors, uint32_t bytesPerColor,
-               uint32_t offset, SkBmpCodec::RowOrder rowOrder, bool isIco);
+            SkBmpCodec::BmpInputFormat inputFormat, uint16_t bitsPerPixel,
+            uint32_t numColors, uint32_t bytesPerColor, uint32_t offset,
+            SkBmpCodec::RowOrder rowOrder, bool isIco);
 
 protected:
 
@@ -68,5 +69,30 @@ private:
     SkAutoTDeleteArray<uint8_t>         fSrcBuffer;
     const bool                          fInIco;
 
+    friend class SkBmpStandardScanlineDecoder;
+
     typedef SkBmpCodec INHERITED;
 };
+
+/*
+ * Scanline decoder for standard bmps
+ */
+class SkBmpStandardScanlineDecoder : public SkScanlineDecoder {
+public:
+    SkBmpStandardScanlineDecoder(SkBmpStandardCodec* codec);
+
+    SkCodec::Result onStart(const SkImageInfo& dstInfo, const SkCodec::Options& options,
+                            SkPMColor inputColorPtr[], int* inputColorCount) override;
+
+    SkCodec::Result onGetScanlines(void* dst, int count, size_t rowBytes) override;
+
+    // TODO(msarett): Override default skipping with something more clever.
+    // TODO(msarett): Consider other optimizations for this codec.
+
+private:
+    SkAutoTDelete<SkBmpStandardCodec> fCodec;
+    SkImageInfo                       fDstInfo;
+    SkCodec::Options                  fOpts;
+
+    typedef SkScanlineDecoder INHERITED;
+};