Fold DataProviders into parent classes

xfa/fwl/core/ifwl_datetimepicker.h

Index: xfa/fwl/core/ifwl_datetimepicker.h
diff --git a/xfa/fwl/core/ifwl_datetimepicker.h b/xfa/fwl/core/ifwl_datetimepicker.h
index 8ebe54ad25a9c7a69b9631da906357e1a62e22bb..6adfe934cc45288c9fb3635aa72fcde4e6fc16af 100644
--- a/xfa/fwl/core/ifwl_datetimepicker.h
+++ b/xfa/fwl/core/ifwl_datetimepicker.h
@@ -60,7 +60,7 @@ class IFWL_DateTimePickerDP : public IFWL_DataProvider {
                              int32_t& iDay) = 0;
 };
 
-class IFWL_DateTimePicker : public IFWL_Widget {
+class IFWL_DateTimePicker : public IFWL_Widget, public IFWL_MonthCalendarDP {
  public:
   explicit IFWL_DateTimePicker(
       const IFWL_App* app,
@@ -114,23 +114,14 @@ class IFWL_DateTimePicker : public IFWL_Widget {
   IFWL_FormProxy* GetFormProxy() const { return m_pForm.get(); }
 
  protected:
-  class CFWL_MonthCalendarImpDP : public IFWL_MonthCalendarDP {
-   public:
-    CFWL_MonthCalendarImpDP();
+  // IFWL_DataProvider
+  FWL_Error GetCaption(IFWL_Widget* pWidget,
+                       CFX_WideString& wsCaption) override;
 
-    // IFWL_DataProvider
-    FWL_Error GetCaption(IFWL_Widget* pWidget,
-                         CFX_WideString& wsCaption) override;
-
-    // IFWL_MonthCalendarDP
-    int32_t GetCurDay(IFWL_Widget* pWidget) override;
-    int32_t GetCurMonth(IFWL_Widget* pWidget) override;
-    int32_t GetCurYear(IFWL_Widget* pWidget) override;
-
-    int32_t m_iCurDay;
-    int32_t m_iCurYear;
-    int32_t m_iCurMonth;
-  };
+  // IFWL_MonthCalendarDP
+  int32_t GetCurDay(IFWL_Widget* pWidget) override;
+  int32_t GetCurMonth(IFWL_Widget* pWidget) override;
+  int32_t GetCurYear(IFWL_Widget* pWidget) override;
 
   void DrawDropDownButton(CFX_Graphics* pGraphics,
                           IFWL_ThemeProvider* pTheme,
@@ -142,6 +133,10 @@ class IFWL_DateTimePicker : public IFWL_Widget {
   void ReSetEditAlignment();
   void InitProxyForm();
 
+  int32_t m_iCurDay;
+  int32_t m_iCurYear;
+  int32_t m_iCurMonth;
+
   CFX_RectF m_rtBtn;
   CFX_RectF m_rtClient;
   int32_t m_iBtnState;
@@ -153,7 +148,6 @@ class IFWL_DateTimePicker : public IFWL_Widget {
   std::unique_ptr<IFWL_DateTimeCalendar> m_pMonthCal;
   std::unique_ptr<IFWL_FormProxy> m_pForm;
   FX_FLOAT m_fBtn;
-  CFWL_MonthCalendarImpDP m_MonthCalendarDP;
 
  private:
   FWL_Error DisForm_Initialize();