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..97c22be78a9db46f5be34c248206ae82b34f5f1d 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 SkTArray.

[scroggo, 2015/12/02 16:27:03]

SkTArray is an implementation detail that isn't necessary in this comment.

[msarett, 2015/12/03 19:19:16]

Done.

+     *
+     * @return the index of the matching codec or -1 if there is no
+     *         matching codec between startIndex and the end of
+     *         the SkTArray.
+     */
+    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
+    // fCodec to one of the fEmbeddedCodecs, if it can find a codec of the
+    // appropriate size.  We will use fCodec for subsequent calls to
+    // onGetScanlines() or onSkipScanlines().
+    // fCodec is owned by this class, but should not be an SkAutoTDelete.
+    // It will be deleted by the destructor of fEmbeddedCodecs.
+    SkCodec* fCodec;

[scroggo, 2015/12/02 16:27:03]

I think this should have a name that indicates that this is used for scanline
decoding (or for an in progress decode). Maybe fCurrScanlineCodec? That's
awfully cumbersome :(

[msarett, 2015/12/03 19:19:16]

Agreed.  fCurrScanlineCodec it is...I can't think of anything better.

 
     typedef SkCodec INHERITED;
 };