Change mojo geometry structs from using type converters to StructTraits.

mash/browser/browser.cc

Index: mash/browser/browser.cc
diff --git a/mash/browser/browser.cc b/mash/browser/browser.cc
index 01c4ad33d01a286892000952fd835a2da34a79cd..eab9a9d5620008ccd9fca075917200844259fc8b 100644
--- a/mash/browser/browser.cc
+++ b/mash/browser/browser.cc
@@ -14,7 +14,6 @@
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_tree_connection.h"
 #include "mash/public/interfaces/launchable.mojom.h"
-#include "mojo/converters/geometry/geometry_type_converters.h"
 #include "mojo/public/c/system/main.h"
 #include "services/navigation/public/interfaces/view.mojom.h"
 #include "services/shell/public/cpp/application_runner.h"
@@ -280,12 +279,12 @@ class UI : public views::WidgetDelegateView,
   void ViewCreated(navigation::mojom::ViewPtr view,
                    navigation::mojom::ViewClientRequest request,
                    bool is_popup,
-                   mojo::RectPtr initial_rect,
+                   const gfx::Rect& initial_rect,
                    bool user_gesture) override {
     views::Widget* window = views::Widget::CreateWindowWithContextAndBounds(
         new UI(browser_, is_popup ? UI::Type::POPUP : UI::Type::WINDOW,
                std::move(view), std::move(request)),
-        nullptr, initial_rect.To<gfx::Rect>());
+        nullptr, initial_rect);
     window->Show();
     browser_->AddWindow(window);
   }