refactor: use views::Widget on macOS

atom/browser/ui/cocoa/atom_native_widget_mac.h

@@ -11,7 +11,8 @@ namespace atom {
 
 class AtomNativeWidgetMac : public views::NativeWidgetMac {
  public:
-  explicit AtomNativeWidgetMac(views::internal::NativeWidgetDelegate* delegate);
+  AtomNativeWidgetMac(NSUInteger style_mask,
+                      views::internal::NativeWidgetDelegate* delegate);
   ~AtomNativeWidgetMac() override;
 
  protected:
@@ -20,6 +21,8 @@ class AtomNativeWidgetMac : public views::NativeWidgetMac {
       const views::Widget::InitParams& params) override;
 
  private:
+  NSUInteger style_mask_;
+
   DISALLOW_COPY_AND_ASSIGN(AtomNativeWidgetMac);
 };
 

atom/browser/ui/cocoa/atom_native_widget_mac.mm

@@ -4,17 +4,26 @@
 
 #include "atom/browser/ui/cocoa/atom_native_widget_mac.h"
 
+#include "atom/browser/ui/cocoa/atom_ns_window.h"
+#include "ui/base/cocoa/window_size_constants.h"
+
 namespace atom {
 
 AtomNativeWidgetMac::AtomNativeWidgetMac(
+    NSUInteger style_mask,
     views::internal::NativeWidgetDelegate* delegate)
-    : views::NativeWidgetMac(delegate) {}
+    : views::NativeWidgetMac(delegate),
+      style_mask_(style_mask) {}
 
 AtomNativeWidgetMac::~AtomNativeWidgetMac() {}
 
 NativeWidgetMacNSWindow* AtomNativeWidgetMac::CreateNSWindow(
     const views::Widget::InitParams& params) {
-  return views::NativeWidgetMac::CreateNSWindow(params);
+  return [[[AtomNSWindow alloc]
+      initWithContentRect:ui::kWindowSizeDeterminedLater
+                styleMask:style_mask_
+                  backing:NSBackingStoreBuffered
+                    defer:YES] autorelease];
 }
 
 }  // namespace atom

atom/browser/ui/cocoa/atom_ns_window.h

@@ -26,7 +26,7 @@ class ScopedDisableResize {
 
 }  // namespace atom
 
-@interface AtomNSWindow : EventDispatchingWindow {
+@interface AtomNSWindow : NativeWidgetMacNSWindow {
  @private
   atom::NativeWindowMac* shell_;
   CGFloat windowButtonsInterButtonSpacing_;

atom/browser/ui/cocoa/atom_ns_window_delegate.h

@@ -13,9 +13,9 @@ namespace atom {
 class NativeWindowMac;
 }
 
-@interface AtomNSWindowDelegate : NSObject<NSWindowDelegate,
-                                           NSTouchBarDelegate,
-                                           QLPreviewPanelDataSource> {
+@interface AtomNSWindowDelegate :
+    ViewsNSWindowDelegate<NSTouchBarDelegate,
+                          QLPreviewPanelDataSource> {
  @private
   atom::NativeWindowMac* shell_;
   bool is_zooming_;

atom/browser/ui/cocoa/atom_ns_window_delegate.mm

@@ -9,11 +9,21 @@
 #include "atom/browser/ui/cocoa/atom_preview_item.h"
 #include "atom/browser/ui/cocoa/atom_touch_bar.h"
 #include "base/mac/mac_util.h"
+#include "ui/views/widget/native_widget_mac.h"
 
 @implementation AtomNSWindowDelegate
 
 - (id)initWithShell:(atom::NativeWindowMac*)shell {
-  if ((self = [super init])) {
+  // The views library assumes the window delegate must be an instance of
+  // ViewsNSWindowDelegate, since we don't have a way to override the creation
+  // of NSWindowDelegate, we have to dynamically replace the window delegate
+  // on the fly.
+  // TODO(zcbenz): Add interface in NativeWidgetMac to allow overriding creating
+  // window delegate.
+  views::BridgedNativeWidget* bridget_view =
+      views::NativeWidgetMac::GetBridgeForNativeWindow(
+          shell->GetNativeWindow());
+  if ((self = [super initWithBridgedNativeWidget:bridget_view])) {
     shell_ = shell;
     is_zooming_ = false;
     level_ = [shell_->GetNativeWindow() level];

atom/browser/ui/cocoa/views_delegate_mac.mm

@@ -16,8 +16,7 @@ ViewsDelegateMac::~ViewsDelegateMac() {}
 void ViewsDelegateMac::OnBeforeWidgetInit(
     views::Widget::InitParams* params,
     views::internal::NativeWidgetDelegate* delegate) {
-  if (!params->native_widget)
-    params->native_widget = new views::NativeWidgetMac(delegate);
+  DCHECK(params->native_widget);
 }
 
 ui::ContextFactory* ViewsDelegateMac::GetContextFactory() {