Move resize_callback field from WindowBuilder into WindowAttributes struct

src/lib.rs

@@ -107,10 +107,6 @@ pub struct WindowBuilder {
 
     /// Platform-specific configuration.
     platform_specific: platform::PlatformSpecificWindowBuilderAttributes,
-
-    /// A function called upon resizing, necessary to receive resize events on Mac and possibly
-    /// other systems.
-    window_resize_callback: Option<fn(u32, u32)>,
 }
 
 /// Error that can happen while creating a window or a headless renderer.
@@ -263,6 +259,10 @@ pub struct WindowAttributes {
     /// [iOS only] Enable multitouch, see [UIView#multipleTouchEnabled]
     /// (https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIView_Class/#//apple_ref/occ/instp/UIView/multipleTouchEnabled)
     pub multitouch: bool,
+
+    /// A function called upon resizing, necessary to receive resize events on Mac and possibly
+    /// other systems.
+    pub resize_callback: Option<fn(u32, u32)>,
 }
 
 impl Default for WindowAttributes {
@@ -278,6 +278,7 @@ impl Default for WindowAttributes {
             transparent: false,
             decorations: true,
             multitouch: false,
+            resize_callback: None,
         }
     }
 }