Change IFWL_Widget to store a single delegate.

xfa/fxfa/app/xfa_ffpushbutton.cpp

Index: xfa/fxfa/app/xfa_ffpushbutton.cpp
diff --git a/xfa/fxfa/app/xfa_ffpushbutton.cpp b/xfa/fxfa/app/xfa_ffpushbutton.cpp
index e64858101117f21861ad3e2a87218a3867398825..d5ad72cf3ba18910798ad7f2db955f6dae4ca0d8 100644
--- a/xfa/fxfa/app/xfa_ffpushbutton.cpp
+++ b/xfa/fxfa/app/xfa_ffpushbutton.cpp
@@ -6,9 +6,11 @@
 
 #include "xfa/fxfa/app/xfa_ffpushbutton.h"
 
+#include "third_party/base/ptr_util.h"
 #include "xfa/fwl/core/cfwl_pushbutton.h"
 #include "xfa/fwl/core/cfwl_widgetmgr.h"
 #include "xfa/fwl/core/fwl_noteimp.h"
+#include "xfa/fxfa/app/cxfa_ffpushbuttondelegate.h"
 #include "xfa/fxfa/app/xfa_fffield.h"
 #include "xfa/fxfa/app/xfa_ffwidgetacc.h"
 #include "xfa/fxfa/app/xfa_textlayout.h"
@@ -24,11 +26,12 @@ CXFA_FFPushButton::CXFA_FFPushButton(CXFA_FFPageView* pPageView,
       m_pRolloverTextLayout(nullptr),
       m_pDownTextLayout(nullptr),
       m_pDownProvider(nullptr),
-      m_pRollProvider(nullptr),
-      m_pOldDelegate(nullptr) {}
+      m_pRollProvider(nullptr) {}
+
 CXFA_FFPushButton::~CXFA_FFPushButton() {
   CXFA_FFPushButton::UnloadWidget();
 }
+
 void CXFA_FFPushButton::RenderWidget(CFX_Graphics* pGS,
                                      CFX_Matrix* pMatrix,
                                      uint32_t dwStatus) {
@@ -55,8 +58,8 @@ FX_BOOL CXFA_FFPushButton::LoadWidget() {
   CFWL_PushButton* pPushButton = new CFWL_PushButton(GetFWLApp());
   pPushButton->Initialize();
 
-  m_pOldDelegate = pPushButton->GetCurrentDelegate();
-  pPushButton->SetCurrentDelegate(this);
+  pPushButton->SetDelegate(pdfium::MakeUnique<CXFA_FFPushButtonDelegate>(
+      pPushButton->ReleaseDelegate(), this));
 
   m_pNormalWidget = pPushButton;
   m_pNormalWidget->SetLayoutItem(this);
@@ -201,47 +204,3 @@ void CXFA_FFPushButton::RenderHighlightCaption(CFX_Graphics* pGS,
     }
   }
 }
-
-void CXFA_FFPushButton::OnProcessMessage(CFWL_Message* pMessage) {
-  m_pOldDelegate->OnProcessMessage(pMessage);
-}
-
-void CXFA_FFPushButton::OnProcessEvent(CFWL_Event* pEvent) {
-  m_pOldDelegate->OnProcessEvent(pEvent);
-  CXFA_FFField::OnProcessEvent(pEvent);
-}
-
-void CXFA_FFPushButton::OnDrawWidget(CFX_Graphics* pGraphics,
-                                     const CFX_Matrix* pMatrix) {
-  if (m_pNormalWidget->GetStylesEx() & XFA_FWL_PSBSTYLEEXT_HiliteInverted) {
-    if ((m_pNormalWidget->GetStates() & FWL_STATE_PSB_Pressed) &&
-        (m_pNormalWidget->GetStates() & FWL_STATE_PSB_Hovered)) {
-      CFX_RectF rtFill;
-      m_pNormalWidget->GetWidgetRect(rtFill);
-      rtFill.left = rtFill.top = 0;
-      FX_FLOAT fLineWith = GetLineWidth();
-      rtFill.Deflate(fLineWith, fLineWith);
-      CFX_Color cr(FXARGB_MAKE(128, 128, 255, 255));
-      pGraphics->SetFillColor(&cr);
-      CFX_Path path;
-      path.Create();
-      path.AddRectangle(rtFill.left, rtFill.top, rtFill.width, rtFill.height);
-      pGraphics->FillPath(&path, FXFILL_WINDING, (CFX_Matrix*)pMatrix);
-    }
-  } else if (m_pNormalWidget->GetStylesEx() &
-             XFA_FWL_PSBSTYLEEXT_HiliteOutLine) {
-    if ((m_pNormalWidget->GetStates() & FWL_STATE_PSB_Pressed) &&
-        (m_pNormalWidget->GetStates() & FWL_STATE_PSB_Hovered)) {
-      FX_FLOAT fLineWidth = GetLineWidth();
-      CFX_Color cr(FXARGB_MAKE(255, 128, 255, 255));
-      pGraphics->SetStrokeColor(&cr);
-      pGraphics->SetLineWidth(fLineWidth);
-      CFX_Path path;
-      path.Create();
-      CFX_RectF rect;
-      m_pNormalWidget->GetWidgetRect(rect);
-      path.AddRectangle(0, 0, rect.width, rect.height);
-      pGraphics->StrokePath(&path, (CFX_Matrix*)pMatrix);
-    }
-  }
-}