Select the button size appropriate for the current DPI initially

Don't just update the bitmaps size when we receive the DPI changed
event, but also use size appropriate for the current DPI initially.

src/msw/anybutton.cpp

@@ -105,9 +105,10 @@ extern wxWindowMSW *wxWindowBeingErased; // From src/msw/window.cpp
 class wxButtonImageData: public wxObject
 {
 public:
-    explicit wxButtonImageData(const wxBitmapBundle& normalBundle)
-        : m_bitmapSize(normalBundle.GetDefaultSize())
+    wxButtonImageData(wxWindow* btn, const wxBitmapBundle& normalBundle)
     {
+        m_bitmapSize = normalBundle.GetDefaultSize() * btn->GetDPIScaleFactor();
+
         m_bitmapBundles[wxAnyButton::State_Normal] = normalBundle;
     }
 
@@ -178,7 +179,7 @@ class wxODButtonImageData : public wxButtonImageData
 {
 public:
     wxODButtonImageData(wxAnyButton *btn, const wxBitmapBundle& bitmapBundle)
-        : wxButtonImageData(bitmapBundle)
+        : wxButtonImageData(btn, bitmapBundle)
     {
         SetBitmap(GetBitmapFromBundle(bitmapBundle),
                   wxAnyButton::State_Normal);
@@ -252,7 +253,7 @@ public:
     // we must be constructed with the size of our images as we need to create
     // the image list
     wxXPButtonImageData(wxAnyButton *btn, const wxBitmapBundle& bitmapBundle)
-        : wxButtonImageData(bitmapBundle),
+        : wxButtonImageData(btn, bitmapBundle),
           m_hwndBtn(GetHwndOf(btn))
     {
         InitImageList();