cc: Specify rasterization color space

ui/gfx/color_space.h

Index: ui/gfx/color_space.h
diff --git a/ui/gfx/color_space.h b/ui/gfx/color_space.h
index 117f1a75cf411395448ac975be148a7c738ffedb..138de565f5d02802ad33a087649104c68a114a0e 100644
--- a/ui/gfx/color_space.h
+++ b/ui/gfx/color_space.h
@@ -144,6 +144,11 @@ class GFX_EXPORT ColorSpace {
   // range, and unspecified spaces.
   sk_sp<SkColorSpace> ToSkColorSpace() const;
 
+  // Return an SkColorSpace that represents this color space, with output-space
+  // blending (which is only linear for color spaces with a linear tranasfer
+  // function).
+  sk_sp<SkColorSpace> ToNonlinearBlendedSkColorSpace() const;
+
   // Populate |icc_profile| with an ICC profile that represents this color
   // space. Returns false if this space is not representable. This ICC profile
   // will be constructed ignoring the range adjust and transfer matrices (this