Extend the geometry APIs.

mojo/services/geometry/interfaces/geometry.mojom

Index: mojo/services/geometry/interfaces/geometry.mojom
diff --git a/mojo/services/geometry/interfaces/geometry.mojom b/mojo/services/geometry/interfaces/geometry.mojom
index a6d2d4ea2dd0548647f1c62ec2f8f6ea88138e2a..1f882b6ad3eb558f978568f08cccf9ecfee127d8 100644
--- a/mojo/services/geometry/interfaces/geometry.mojom
+++ b/mojo/services/geometry/interfaces/geometry.mojom
@@ -34,6 +34,21 @@ struct RectF {
   float height;
 };
 
+struct RRect {
+  int32 x;
+  int32 y;
+  int32 width;
+  int32 height;
+  int32 top_left_radius_x;
+  int32 top_left_radius_y;
+  int32 top_right_radius_x;
+  int32 top_right_radius_y;
+  int32 bottom_left_radius_x;
+  int32 bottom_left_radius_y;
+  int32 bottom_right_radius_x;
+  int32 bottom_right_radius_y;

[abarth-chromium, 2015/12/10 22:49:53]

It's very common for all of these radii to have the same value.  In SkRRect,
there's a bunch of work to take faster paths for simpler cases.  If/when we
convert this class into an SkRRect, we should make sure we're still hitting
those fast paths.

[jeffbrown, 2015/12/11 19:40:55]

Skia auto-detects the type when provided with the more generalized set of
parameters.

I was debating whether to only support simple cases in the compositor but this
wasn't any more trouble and it makes for easier interop with Flutter's layer
system.  I expect we'll revisit this sooner or later depending on how things
work out.

+};
+
 struct Transform {
   // Row major order.
   array<float, 16> matrix;