mash: Fix create fullscreen widget

chrome/browser/chromeos/login/ui/lock_window.cc

Index: chrome/browser/chromeos/login/ui/lock_window.cc
diff --git a/chrome/browser/chromeos/login/ui/lock_window.cc b/chrome/browser/chromeos/login/ui/lock_window.cc
index c810969bf7f60444fbb15348b8c1c2c10633da4b..8592488ed06f43bf6f928ac94522deb5456c3114 100644
--- a/chrome/browser/chromeos/login/ui/lock_window.cc
+++ b/chrome/browser/chromeos/login/ui/lock_window.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/ui/ash/ash_util.h"
 #include "services/ui/public/cpp/property_type_converters.h"
 #include "services/ui/public/interfaces/window_manager.mojom.h"
+#include "ui/aura/mus/property_converter.h"
 #include "ui/aura/window.h"
 #include "ui/events/gestures/gesture_recognizer.h"
 
@@ -28,6 +29,10 @@ LockWindow::LockWindow(views::View* initially_focused_view)
     using ui::mojom::WindowManager;
     params.mus_properties[WindowManager::kContainerId_InitProperty] =
         mojo::ConvertTo<std::vector<uint8_t>>(kLockContainer);
+    params.mus_properties[WindowManager::kShowState_Property] =

[James Cook, 2017/04/25 19:42:28]

It seems bad that setting Views::Widget::InitParams::show_state =
ui::SHOW_STATE_FULLSCREEN is not sufficient to make this work.

I wonder if this should be fixed lower-down, like in views.

[sky, 2017/04/25 22:35:43]

Setting the SHOW_STATE_FULLSCREEN on the init params should mean we end up in
DesktopWindowTreeHostMus::ShowWindowWithState and the fullscreenstate is then
set on the window. Setting the kShowStateKey should make it so ash sees the
change as well. Is that not working?
Is the issue that the window needs to be fullscreen before parented in ash?

+        mojo::ConvertTo<std::vector<uint8_t>>(
+            static_cast<aura::PropertyConverter::PrimitiveType>(
+                ui::mojom::ShowState::FULLSCREEN));
   } else {
     params.parent = ash::Shell::GetContainer(ash::Shell::GetPrimaryRootWindow(),
                                              kLockContainer);