Make some more CFWL_Widget sub-widgets const members.

Change-Id: I771129ed8fe052bbc5bbd0609dc381551bf595af
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/72911
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/xfa/fwl/cfwl_datetimepicker.cpp b/xfa/fwl/cfwl_datetimepicker.cpp
index aec4edf..8f121e3 100644
--- a/xfa/fwl/cfwl_datetimepicker.cpp
+++ b/xfa/fwl/cfwl_datetimepicker.cpp
@@ -24,21 +24,18 @@
 
 }  // namespace
 CFWL_DateTimePicker::CFWL_DateTimePicker(const CFWL_App* app)
-    : CFWL_Widget(app, Properties(), nullptr) {
-  m_Properties.m_dwStyleExes = FWL_STYLEEXT_DTP_ShortDateFormat;
-
-  Properties monthProp;
-  monthProp.m_dwStyles = FWL_WGTSTYLE_Popup | FWL_WGTSTYLE_Border;
-  monthProp.m_dwStates = FWL_WGTSTATE_Invisible;
-  m_pMonthCal =
-      std::make_unique<CFWL_MonthCalendar>(GetFWLApp(), monthProp, this);
-
+    : CFWL_Widget(app,
+                  Properties{0, FWL_STYLEEXT_DTP_ShortDateFormat, 0},
+                  nullptr),
+      m_pEdit(std::make_unique<CFWL_DateTimeEdit>(app, Properties(), this)),
+      m_pMonthCal(std::make_unique<CFWL_MonthCalendar>(
+          app,
+          Properties{FWL_WGTSTYLE_Popup | FWL_WGTSTYLE_Border, 0,
+                     FWL_WGTSTATE_Invisible},
+          this)) {
   m_pMonthCal->SetWidgetRect(
       CFX_RectF(0, 0, m_pMonthCal->GetAutosizedWidgetRect().Size()));
 
-  m_pEdit =
-      std::make_unique<CFWL_DateTimeEdit>(GetFWLApp(), Properties(), this);
-
   RegisterEventTarget(m_pMonthCal.get());
   RegisterEventTarget(m_pEdit.get());
 }
diff --git a/xfa/fwl/cfwl_datetimepicker.h b/xfa/fwl/cfwl_datetimepicker.h
index 701f586..83eeb88 100644
--- a/xfa/fwl/cfwl_datetimepicker.h
+++ b/xfa/fwl/cfwl_datetimepicker.h
@@ -97,8 +97,8 @@
   float m_fBtn = 0.0f;
   CFX_RectF m_BtnRect;
   CFX_RectF m_ClientRect;
-  std::unique_ptr<CFWL_DateTimeEdit> m_pEdit;
-  std::unique_ptr<CFWL_MonthCalendar> m_pMonthCal;
+  std::unique_ptr<CFWL_DateTimeEdit> const m_pEdit;
+  std::unique_ptr<CFWL_MonthCalendar> const m_pMonthCal;
 };
 
 #endif  // XFA_FWL_CFWL_DATETIMEPICKER_H_
diff --git a/xfa/fwl/cfwl_edit.cpp b/xfa/fwl/cfwl_edit.cpp
index c3671c8..47a9bd6 100644
--- a/xfa/fwl/cfwl_edit.cpp
+++ b/xfa/fwl/cfwl_edit.cpp
@@ -835,20 +835,22 @@
   if (m_pVertScrollBar)
     return;
 
-  Properties prop;
-  prop.m_dwStyleExes = FWL_STYLEEXT_SCB_Vert;
-  prop.m_dwStates = FWL_WGTSTATE_Disabled | FWL_WGTSTATE_Invisible;
-  m_pVertScrollBar = std::make_unique<CFWL_ScrollBar>(GetFWLApp(), prop, this);
+  m_pVertScrollBar = std::make_unique<CFWL_ScrollBar>(
+      GetFWLApp(),
+      Properties{0, FWL_STYLEEXT_SCB_Vert,
+                 FWL_WGTSTATE_Disabled | FWL_WGTSTATE_Invisible},
+      this);
 }
 
 void CFWL_Edit::InitHorizontalScrollBar() {
   if (m_pHorzScrollBar)
     return;
 
-  Properties prop;
-  prop.m_dwStyleExes = FWL_STYLEEXT_SCB_Horz;
-  prop.m_dwStates = FWL_WGTSTATE_Disabled | FWL_WGTSTATE_Invisible;
-  m_pHorzScrollBar = std::make_unique<CFWL_ScrollBar>(GetFWLApp(), prop, this);
+  m_pHorzScrollBar = std::make_unique<CFWL_ScrollBar>(
+      GetFWLApp(),
+      Properties{0, FWL_STYLEEXT_SCB_Horz,
+                 FWL_WGTSTATE_Disabled | FWL_WGTSTATE_Invisible},
+      this);
 }
 
 void CFWL_Edit::ShowCaret(CFX_RectF* pRect) {
diff --git a/xfa/fwl/cfwl_listbox.cpp b/xfa/fwl/cfwl_listbox.cpp
index ae8f323..61fb83a 100644
--- a/xfa/fwl/cfwl_listbox.cpp
+++ b/xfa/fwl/cfwl_listbox.cpp
@@ -589,20 +589,18 @@
   if (m_pVertScrollBar)
     return;
 
-  Properties prop;
-  prop.m_dwStyleExes = FWL_STYLEEXT_SCB_Vert;
-  prop.m_dwStates = FWL_WGTSTATE_Invisible;
-  m_pVertScrollBar = std::make_unique<CFWL_ScrollBar>(GetFWLApp(), prop, this);
+  m_pVertScrollBar = std::make_unique<CFWL_ScrollBar>(
+      GetFWLApp(), Properties{0, FWL_STYLEEXT_SCB_Vert, FWL_WGTSTATE_Invisible},
+      this);
 }
 
 void CFWL_ListBox::InitHorizontalScrollBar() {
   if (m_pHorzScrollBar)
     return;
 
-  Properties prop;
-  prop.m_dwStyleExes = FWL_STYLEEXT_SCB_Horz;
-  prop.m_dwStates = FWL_WGTSTATE_Invisible;
-  m_pHorzScrollBar = std::make_unique<CFWL_ScrollBar>(GetFWLApp(), prop, this);
+  m_pHorzScrollBar = std::make_unique<CFWL_ScrollBar>(
+      GetFWLApp(), Properties{0, FWL_STYLEEXT_SCB_Horz, FWL_WGTSTATE_Invisible},
+      this);
 }
 
 bool CFWL_ListBox::IsShowScrollBar(bool bVert) {