diff --git a/fpdfsdk/pwl/cpwl_wnd.cpp b/fpdfsdk/pwl/cpwl_wnd.cpp
index b8093c6..4a37278 100644
--- a/fpdfsdk/pwl/cpwl_wnd.cpp
+++ b/fpdfsdk/pwl/cpwl_wnd.cpp
@@ -68,13 +68,9 @@
   }
 
   void SetFocus(CPWL_Wnd* pWnd) {
-    m_KeyboardPaths.clear();
+    m_KeyboardPaths = pWnd->GetAncestors();
     m_pMainKeyboardWnd = pWnd;
-    CPWL_Wnd* pParent = pWnd;
-    while (pParent) {
-      m_KeyboardPaths.emplace_back(pParent);
-      pParent = pParent->GetParentWindow();
-    }
+
     // Note, pWnd may get destroyed in the OnSetFocus call.
     pWnd->OnSetFocus();
   }
@@ -93,13 +89,7 @@
     m_KeyboardPaths.clear();
   }
 
-  void SetCapture(CPWL_Wnd* pWnd) {
-    m_MousePaths.clear();
-    while (pWnd) {
-      m_MousePaths.emplace_back(pWnd);
-      pWnd = pWnd->GetParentWindow();
-    }
-  }
+  void SetCapture(CPWL_Wnd* pWnd) { m_MousePaths = pWnd->GetAncestors(); }
 
   void ReleaseCapture() { m_MousePaths.clear(); }
 
@@ -543,6 +533,14 @@
   return m_pAttachedData ? m_pAttachedData->Clone() : nullptr;
 }
 
+std::vector<UnownedPtr<CPWL_Wnd>> CPWL_Wnd::GetAncestors() {
+  std::vector<UnownedPtr<CPWL_Wnd>> results;
+  for (CPWL_Wnd* pWnd = this; pWnd; pWnd = pWnd->GetParentWindow()) {
+    results.emplace_back(pWnd);
+  }
+  return results;
+}
+
 bool CPWL_Wnd::WndHitTest(const CFX_PointF& point) const {
   return IsValid() && IsVisible() && GetWindowRect().Contains(point);
 }
diff --git a/fpdfsdk/pwl/cpwl_wnd.h b/fpdfsdk/pwl/cpwl_wnd.h
index 3f4931a..f346e52 100644
--- a/fpdfsdk/pwl/cpwl_wnd.h
+++ b/fpdfsdk/pwl/cpwl_wnd.h
@@ -201,11 +201,11 @@
   void RemoveFlag(uint32_t dwFlags);
   void SetClipRect(const CFX_FloatRect& rect);
 
-  CPWL_Wnd* GetParentWindow() const { return m_pParent.Get(); }
   IPWL_FillerNotify::PerWindowData* GetAttachedData() const {
     return m_pAttachedData.get();
   }
   std::unique_ptr<IPWL_FillerNotify::PerWindowData> CloneAttachedData() const;
+  std::vector<UnownedPtr<CPWL_Wnd>> GetAncestors();
 
   bool WndHitTest(const CFX_PointF& point) const;
   bool ClientHitTest(const CFX_PointF& point) const;
@@ -241,6 +241,7 @@
     return m_CreationParams.pFillerNotify.Get();
   }
 
+  CPWL_Wnd* GetParentWindow() const { return m_pParent.Get(); }
   CPWL_ScrollBar* GetVScrollBar() const;
 
   // Returns |true| iff this instance is still allocated.