Make SkAndroidCodec support ico

src/codec/SkCodec_libico.h

Index: src/codec/SkCodec_libico.h
diff --git a/src/codec/SkCodec_libico.h b/src/codec/SkCodec_libico.h
index 92675f4d740ea241de38d00ddbf4a768040c8b47..a1d99b884dac9c3b68acbc03b7e0257455493d00 100644
--- a/src/codec/SkCodec_libico.h
+++ b/src/codec/SkCodec_libico.h
@@ -47,17 +47,45 @@ protected:
         return kICO_SkEncodedFormat;
     }
 
+    SkScanlineOrder onGetScanlineOrder() const override;
+
 private:
 
+    Result onStartScanlineDecode(const SkImageInfo& dstInfo, const SkCodec::Options& options,
+            SkPMColor inputColorPtr[], int* inputColorCount) override;
+
+    int onGetScanlines(void* dst, int count, size_t rowBytes) override;
+
+    bool onSkipScanlines(int count) override;
+
+    SkSampler* getSampler(bool createIfNecessary) override;
+
+    /*
+     * Searches fEmbeddedCodecs for a codec that matches requestedSize.
+     * The search starts at startIndex and ends when an appropriate codec
+     * is found, or we have reached the end of the array.
+     *
+     * @return the index of the matching codec or -1 if there is no
+     *         matching codec between startIndex and the end of
+     *         the array.
+     */
+    int chooseCodec(const SkISize& requestedSize, int startIndex);
+
     /*
      * Constructor called by NewFromStream
      * @param embeddedCodecs codecs for the embedded images, takes ownership
      */
-    SkIcoCodec(const SkImageInfo& srcInfo,
-               SkTArray<SkAutoTDelete<SkCodec>, true>* embeddedCodecs);
+    SkIcoCodec(const SkImageInfo& srcInfo, SkTArray<SkAutoTDelete<SkCodec>, true>* embeddedCodecs);
+
+    SkAutoTDelete<SkTArray<SkAutoTDelete<SkCodec>, true>> fEmbeddedCodecs; // owned
 
-    SkAutoTDelete<SkTArray<SkAutoTDelete<SkCodec>, true>>
-            fEmbeddedCodecs; // owned
+    // Only used by the scanline decoder.  onStartScanlineDecode() will set
+    // fCurrScanlineCodec to one of the fEmbeddedCodecs, if it can find a
+    // codec of the appropriate size.  We will use fCurrScanlineCodec for
+    // subsequent calls to onGetScanlines() or onSkipScanlines().
+    // fCurrScanlineCodec is owned by this class, but should not be an
+    // SkAutoTDelete.  It will be deleted by the destructor of fEmbeddedCodecs.
+    SkCodec* fCurrScanlineCodec;
 
     typedef SkCodec INHERITED;
 };