Add color space to picture image as a creation parameter

This gives a picture image a preferred "native" color space, which
facilitates caching and other things.

BUG=skia:

Change-Id: I95988c14d17f96d7d870b3d1c3b723c36e2c170d
Reviewed-on: https://skia-review.googlesource.com/6158
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/gm/image_shader.cpp b/gm/image_shader.cpp
index 49b1ed5..7803739 100644
--- a/gm/image_shader.cpp
+++ b/gm/image_shader.cpp
@@ -47,7 +47,8 @@
 }
 
 static sk_sp<SkImage> make_pict_gen(GrContext*, SkPicture* pic, const SkImageInfo& info) {
-    return SkImage::MakeFromPicture(sk_ref_sp(pic), info.dimensions(), nullptr, nullptr);
+    return SkImage::MakeFromPicture(sk_ref_sp(pic), info.dimensions(), nullptr, nullptr,
+                                    SkColorSpace::MakeNamed(SkColorSpace::kSRGB_Named));
 }
 
 static sk_sp<SkImage> make_encode_gen(GrContext* ctx, SkPicture* pic, const SkImageInfo& info) {