Change mojo geometry structs from using type converters to StructTraits.

components/mus/public/cpp/lib/window.cc

Index: components/mus/public/cpp/lib/window.cc
diff --git a/components/mus/public/cpp/lib/window.cc b/components/mus/public/cpp/lib/window.cc
index b6a329c6dc94a79f599decd35dbde497bb7ab356..376cff6b6d0865277db064490f0f4d6abbe758e9 100644
--- a/components/mus/public/cpp/lib/window.cc
+++ b/components/mus/public/cpp/lib/window.cc
@@ -474,16 +474,6 @@ std::string Window::GetName() const {
 ////////////////////////////////////////////////////////////////////////////////
 // Window, protected:
 
-namespace {
-
-mojom::ViewportMetricsPtr CreateEmptyViewportMetrics() {
-  mojom::ViewportMetricsPtr metrics = mojom::ViewportMetrics::New();
-  metrics->size_in_pixels = mojo::Size::New();
-  return metrics;
-}
-
-}  // namespace
-
 Window::Window() : Window(nullptr, static_cast<Id>(-1)) {}
 
 Window::~Window() {
@@ -549,7 +539,7 @@ Window::Window(WindowTreeConnection* connection, Id id)
       // Matches aura, see aura::Window for details.
       observers_(base::ObserverList<WindowObserver>::NOTIFY_EXISTING_ONLY),
       input_event_handler_(nullptr),
-      viewport_metrics_(CreateEmptyViewportMetrics()),
+      viewport_metrics_(mojom::ViewportMetrics::New()),
       visible_(false),
       opacity_(1.0f),
       cursor_id_(mojom::Cursor::CURSOR_NULL),