Change mojo geometry structs from using type converters to StructTraits.

ui/gfx/geometry/mojo/geometry.mojom

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // TODO(beng): should be gfx.mojom;
 module mojo;
 
 struct Point {
   int32 x;
   int32 y;
 };
 
 struct PointF {
   float x;
   float y;
 };
 
 struct Size {
   int32 width;
   int32 height;
 };
 
+struct SizeF {
+  int32 width;
+  int32 height;
+};
+
 struct Rect {
   int32 x;
   int32 y;
   int32 width;
   int32 height;
 };
 
 struct RectF {
   float x;
   float y;
   float width;
   float height;
 };
 
 struct Transform {
   // Row major order.
   array<float, 16> matrix;
 };
 
 struct Insets {
   int32 top;
   int32 left;
   int32 bottom;
   int32 right;
 };
+
+struct InsetsF {
+  float top;
+  float left;
+  float bottom;
+  float right;
+};