Added ImageFamily::CreateExact, which scales the best image to size.

ui/gfx/image/image_family.h

Index: ui/gfx/image/image_family.h
diff --git a/ui/gfx/image/image_family.h b/ui/gfx/image/image_family.h
index c092b2a87ca521a4ff78678581fc332b3bfed8fa..e8920b9a88f44bc8530191e4a6dbbbee0da99c27 100644
--- a/ui/gfx/image/image_family.h
+++ b/ui/gfx/image/image_family.h
@@ -136,6 +136,17 @@ class GFX_EXPORT ImageFamily {
   // NULL.
   const gfx::Image* GetBest(const gfx::Size& size) const;
 
+  // Gets an image of size |width|x|height|. If no image of that exact size
+  // exists, chooses the nearest larger image using GetBest() and scales it to
+  // the desired size. If there are no images in the family, returns an empty
+  // image.
+  gfx::Image CreateExact(int width, int height) const;
+
+  // Gets an image of size |size|. If no image of that exact size exists,
+  // chooses the nearest larger image using GetBest() and scales it to the
+  // desired size. If there are no images in the family, returns an empty image.
+  gfx::Image CreateExact(const gfx::Size& size) const;

[Peter Kasting, 2015/11/05 05:49:27]

Does anyone call this variant?  In an ideal world I'd probably force all APIs to
_only_ have Size, Rect, Point, etc. variants and not have any "independent
coordinate" versions, but it seems like 100% of your callers are using the other
form, so maybe we should just have that.

[Matt Giuca, 2015/11/05 06:22:50]

The code I've got lined up behind this uses the gfx::Size variant.

There isn't a lot of existing code using GetBest so if you'd like, I can convert
it all over to use the gfx::Size variant and delete the int,int one. And never
add CreateExact(int,int).

[Peter Kasting, 2015/11/05 06:24:57]

I don't think it's a big deal either way and you own the interface, so I leave
it up to you.

[Robert Sesek, 2015/11/05 16:05:56]

I tend to agree with Peter that it'd be good to only have the gfx-typed variants
of these functions, but I don't feel strongly that way.

[Matt Giuca, 2015/11/06 04:15:18]

OK since neither of you feel strongly, I'll keep it the way it is (for
consistency with GetBest, and because it makes tests slightly less verbose).

+
  private:
   // Find the closest aspect ratio in the map to |desired_aspect|.
   // Ties are broken by the thinner aspect.