Add SkColorSpace::Equals() API

include/core/SkColorSpace.h

Index: include/core/SkColorSpace.h
diff --git a/include/core/SkColorSpace.h b/include/core/SkColorSpace.h
index 9fc5ccde719d7520f6cb40429675efe78e449a5c..8a8387a01b514c94f898375fc4d3e53e1824c505 100644
--- a/include/core/SkColorSpace.h
+++ b/include/core/SkColorSpace.h
@@ -104,6 +104,8 @@ public:
 
     static sk_sp<SkColorSpace> Deserialize(const void* data, size_t length);
 
+    static bool Equals(const SkColorSpace* src, const SkColorSpace* dst);

[reed1, 2016/07/29 22:35:45]

wonder if it should take const& for each, since we don't support null for
either.

[reed1, 2016/08/01 15:08:26]

Perhaps add dox to describe what we do when we see a null (e.g. if one is null
and one is not, we return false, if both are null, we return true, else we do a
deeper compare)

+
 protected:
     SkColorSpace(GammaNamed gammaNamed, const SkMatrix44& toXYZD50, Named named);