Enabling ico decoding with use of png and bmp decoders

src/codec/SkCodec_libico.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCodec.h"
+#include "SkImageInfo.h"
+#include "SkStream.h"
+#include "SkTypes.h"
+
+/*
+ * This class implements the decoding for bmp images
+ */
+class SkIcoCodec : public SkCodec {
+public:
+
+    /*
+     * Checks the start of the stream to see if the image is a Ico or Cur
+     */
+    static bool IsIco(SkStream*);
+
+    /*
+     * Assumes IsIco was called and returned true
+     * Creates an Ico decoder
+     * Reads enough of the stream to determine the image format
+     */
+    static SkCodec* NewFromStream(SkStream*);
+
+protected:
+
+    /*
+     * Chooses the best dimensions given the desired scale
+     */
+    SkISize onGetScaledDimensions(float desiredScale) const SK_OVERRIDE;
+
+    /*
+     * Initiates the Ico decode
+     */
+    Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
+                       size_t dstRowBytes, const Options&, SkPMColor*, int*)
+                       SK_OVERRIDE;
+
+    SkEncodedFormat onGetEncodedFormat() const SK_OVERRIDE {
+        return kICO_SkEncodedFormat;
+    }
+
+private:
+
+    /*
+     * Constructor called by NewFromStream
+     * @param embeddedCodecs codecs for the embedded images, takes ownership
+     */
+    SkIcoCodec(const SkImageInfo& srcInfo,
+               SkTArray<SkAutoTDelete<SkCodec>, true>* embeddedCodecs);
+
+    SkAutoTDelete<SkTArray<SkAutoTDelete<SkCodec>, true>>
+            fEmbeddedCodecs; // owned
+
+    typedef SkCodec INHERITED;
+};