win32: Move to separate directoy

I suspect I may split the win32 code into a few more files, so move it
to its own directory to reduce the clutter.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

src/Makefile.sources

@@ -334,10 +334,14 @@ cairo_quartz_image_sources = cairo-quartz-image-surface.c
 cairo_quartz_font_sources = cairo-quartz-font.c
 
 cairo_win32_headers = cairo-win32.h
-cairo_win32_private = cairo-win32-private.h
-cairo_win32_sources = cairo-win32-surface.c cairo-win32-printing-surface.c
-
-cairo_win32_font_sources = cairo-win32-font.c
+cairo_win32_private = win32/cairo-win32-private.h
+cairo_win32_sources = \
+	win32/cairo-win32-surface.c \
+	win32/cairo-win32-printing-surface.c \
+	$(NULL)
+cairo_win32_font_sources = \
+	win32/cairo-win32-font.c \
+	$(NULL)
 
 cairo_skia_headers = cairo-skia.h
 cairo_skia_cxx_sources = \

src/cairo-win32-surface.c → src/win32/cairo-win32-surface.c

@@ -1747,7 +1747,7 @@ cairo_win32_surface_create (HDC hdc)
 			 NULL, /* device */
 			 _cairo_content_from_format (format));
 
-    return (cairo_surface_t *)surface;
+    return &surface->base;
 }
 
 /**
@@ -1881,24 +1881,13 @@ _cairo_surface_is_win32 (cairo_surface_t *surface)
 HDC
 cairo_win32_surface_get_dc (cairo_surface_t *surface)
 {
-    cairo_win32_surface_t *winsurf;
-
-    if (_cairo_surface_is_win32 (surface)){
-	winsurf = (cairo_win32_surface_t *) surface;
-
-	return winsurf->dc;
-    }
+    if (_cairo_surface_is_win32 (surface))
+	return ((cairo_win32_surface_t *) target)->dc;
 
     if (_cairo_surface_is_paginated (surface)) {
-	cairo_surface_t *target;
-
-	target = _cairo_paginated_surface_get_target (surface);
-
-	if (_cairo_surface_is_win32_printing (target)) {
-	    winsurf = (cairo_win32_surface_t *) target;
-
-	    return winsurf->dc;
-	}
+	cairo_surface_t *target = _cairo_paginated_surface_get_target (surface);
+	if (_cairo_surface_is_win32_printing (target))
+	    return ((cairo_win32_surface_t *) target)->dc;
     }
 
     return NULL;