Remove SetHostSize/Bounds from RootWindow in favor of just calling SetBounds() on host()

ash/display/mirror_window_controller.cc

Index: ash/display/mirror_window_controller.cc
diff --git a/ash/display/mirror_window_controller.cc b/ash/display/mirror_window_controller.cc
index 226b99d9e36a759d06392e3c5302715b01282b4d..54d6764f4e53c15fc05e9c9b752c15175f1419cf 100644
--- a/ash/display/mirror_window_controller.cc
+++ b/ash/display/mirror_window_controller.cc
@@ -204,7 +204,7 @@ void MirrorWindowController::UpdateWindow(const DisplayInfo& display_info) {
   } else {
     GetRootWindowSettings(root_window_->window())->display_id =
         display_info.id();
-    root_window_->SetHostBounds(display_info.bounds_in_native());
+    root_window_->host()->SetBounds(display_info.bounds_in_native());
   }
 
   DisplayManager* display_manager = Shell::GetInstance()->display_manager();