Remove PNM_SCROLLWINDOW and replace with direct method

This CL removes PNM_SCROLLWINDOW from OnNotify and replaces it with a call to
ScrollWindowVerticallyTo.

Change-Id: I62f6da60cdcd4926b0c74b980b3855a28a834411
Reviewed-on: https://pdfium-review.googlesource.com/7253
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>
diff --git a/fpdfsdk/pdfwindow/cpwl_wnd.h b/fpdfsdk/pdfwindow/cpwl_wnd.h
index c9c4130..ab4cf7a 100644
--- a/fpdfsdk/pdfwindow/cpwl_wnd.h
+++ b/fpdfsdk/pdfwindow/cpwl_wnd.h
@@ -74,7 +74,6 @@
 #define PRES_TEXTOVERFLOW 0x0400L
 
 // notification messages
-#define PNM_SCROLLWINDOW 4
 #define PNM_LBUTTONDOWN 5
 #define PNM_LBUTTONUP 6
 #define PNM_MOUSEMOVE 7
@@ -221,6 +220,7 @@
                         intptr_t lParam = 0);
   virtual void SetScrollInfo(const PWL_SCROLL_INFO& info);
   virtual void SetScrollPosition(float pos);
+  virtual void ScrollWindowVertically(float pos);
   virtual void SetFocus();
   virtual void KillFocus();
   virtual void SetCursor();