Fold virtual CPWL_Wnd::OnCreate into subclass constructors.

All they do is twiddle their own CreateParameters.  Since we
now have the create paramters earlier, we need not have a
special method for this.

Change-Id: I5b94c578275c71516afb87bd085f5fb58b3962e2
Reviewed-on: https://pdfium-review.googlesource.com/c/44730
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/fpdfsdk/pwl/cpwl_scroll_bar.cpp b/fpdfsdk/pwl/cpwl_scroll_bar.cpp
index 0209ba0..d3c8e84 100644
--- a/fpdfsdk/pwl/cpwl_scroll_bar.cpp
+++ b/fpdfsdk/pwl/cpwl_scroll_bar.cpp
@@ -111,14 +111,12 @@
                              PWL_SBBUTTON_TYPE eButtonType)
     : CPWL_Wnd(cp, std::move(pAttachedData)),
       m_eScrollBarType(eScrollBarType),
-      m_eSBButtonType(eButtonType) {}
+      m_eSBButtonType(eButtonType) {
+  GetCreationParams()->eCursorType = FXCT_ARROW;
+}
 
 CPWL_SBButton::~CPWL_SBButton() = default;
 
-void CPWL_SBButton::OnCreate(CreateParams* pParamsToAdjust) {
-  pParamsToAdjust->eCursorType = FXCT_ARROW;
-}
-
 void CPWL_SBButton::DrawThisAppearance(CFX_RenderDevice* pDevice,
                                        const CFX_Matrix& mtUser2Device) {
   if (!IsVisible())
@@ -302,14 +300,12 @@
 CPWL_ScrollBar::CPWL_ScrollBar(const CreateParams& cp,
                                std::unique_ptr<PrivateData> pAttachedData,
                                PWL_SCROLLBAR_TYPE sbType)
-    : CPWL_Wnd(cp, std::move(pAttachedData)), m_sbType(sbType) {}
+    : CPWL_Wnd(cp, std::move(pAttachedData)), m_sbType(sbType) {
+  GetCreationParams()->eCursorType = FXCT_ARROW;
+}
 
 CPWL_ScrollBar::~CPWL_ScrollBar() = default;
 
-void CPWL_ScrollBar::OnCreate(CreateParams* pParamsToAdjust) {
-  pParamsToAdjust->eCursorType = FXCT_ARROW;
-}
-
 void CPWL_ScrollBar::OnDestroy() {
   // Until cleanup takes place in the virtual destructor for CPWL_Wnd
   // subclasses, implement the virtual OnDestroy method that does the