Change mojo geometry structs from using type converters to StructTraits.

ui/gfx/geometry/mojo/geometry.mojom

Index: ui/gfx/geometry/mojo/geometry.mojom
diff --git a/ui/gfx/geometry/mojo/geometry.mojom b/ui/gfx/geometry/mojo/geometry.mojom
index 8621f69ced77c2874c9c0aff2081e215a43f3511..89b33a5c3480fbbe409a486d2200c51100fe6b3e 100644
--- a/ui/gfx/geometry/mojo/geometry.mojom
+++ b/ui/gfx/geometry/mojo/geometry.mojom
@@ -20,6 +20,11 @@ struct Size {
   int32 height;
 };
 
+struct SizeF {
+  int32 width;
+  int32 height;
+};
+
 struct Rect {
   int32 x;
   int32 y;
@@ -45,3 +50,10 @@ struct Insets {
   int32 bottom;
   int32 right;
 };
+
+struct InsetsF {
+  float top;
+  float left;
+  float bottom;
+  float right;
+};