Remove unused CFWL_WidgetProperties::m_pOwner.

It is never non-null.
Initialize in header while we're at it.

Change-Id: Ie4663bd4ca99aae2f3c4db8da2b253229955435d
Reviewed-on: https://pdfium-review.googlesource.com/c/49410
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/xfa/fwl/cfwl_widget.h b/xfa/fwl/cfwl_widget.h
index 6585adc..92491a0 100644
--- a/xfa/fwl/cfwl_widget.h
+++ b/xfa/fwl/cfwl_widget.h
@@ -154,7 +154,7 @@
   UnownedPtr<CFWL_WidgetMgr> const m_pWidgetMgr;
   std::unique_ptr<CFWL_WidgetProperties> m_pProperties;
   CFWL_Widget* m_pOuter;
-  int32_t m_iLock;
+  int32_t m_iLock = 0;
 
  private:
   CFWL_Widget* GetParent() const { return m_pWidgetMgr->GetParentWidget(this); }
@@ -166,8 +166,8 @@
   void NotifyDriver();
   bool IsParent(CFWL_Widget* pParent);
 
-  CXFA_FFWidget* m_pLayoutItem;
-  uint32_t m_nEventKey;
+  uint32_t m_nEventKey = 0;
+  CXFA_FFWidget* m_pLayoutItem = nullptr;
   UnownedPtr<IFWL_WidgetDelegate> m_pDelegate;
 };