Make SkAndroidCodec support ico

BUG=skia:

Review URL: https://codereview.chromium.org/1472933002
diff --git a/src/codec/SkAndroidCodec.cpp b/src/codec/SkAndroidCodec.cpp
index cf6e253..c26b3ef 100644
--- a/src/codec/SkAndroidCodec.cpp
+++ b/src/codec/SkAndroidCodec.cpp
@@ -34,11 +34,9 @@
         case kWBMP_SkEncodedFormat:
         case kBMP_SkEncodedFormat:
         case kGIF_SkEncodedFormat:
+        case kICO_SkEncodedFormat:
             return new SkSampledCodec(codec.detach());
         default:
-            // FIXME: SkSampledCodec is temporarily disabled for other formats
-            // while focusing on the formats that are supported by
-            // BitmapRegionDecoder.
             return nullptr;
     }
 }