MacViews: Implement Window-modal dialogs using sheets

ui/views/widget/native_widget_mac.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/widget/native_widget_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_nsobject.h"
@@ skipping 233 matching lines @@
   [window setTitle:new_title];
   return true;
 }
 
 void NativeWidgetMac::SetWindowIcons(const gfx::ImageSkia& window_icon,
                                      const gfx::ImageSkia& app_icon) {
   NOTIMPLEMENTED();
 }
 
 void NativeWidgetMac::InitModalType(ui::ModalType modal_type) {
-  NOTIMPLEMENTED();
+  if (modal_type == ui::MODAL_TYPE_NONE)
+    return;
+
+  // System modal windows not implemented (or used) on Mac.
+  DCHECK_NE(ui::MODAL_TYPE_SYSTEM, modal_type);
+  DCHECK(bridge_->parent());
+  // Everyhing happens upon show.
 }
 
 gfx::Rect NativeWidgetMac::GetWindowBoundsInScreen() const {
   return gfx::ScreenRectFromNSRect([GetNativeWindow() frame]);
 }
 
 gfx::Rect NativeWidgetMac::GetClientAreaBoundsInScreen() const {
   NSWindow* window = GetNativeWindow();
   return gfx::ScreenRectFromNSRect(
       [window contentRectForFrameRect:[window frame]]);
@@ skipping 27 matching lines @@
 }
 
 void NativeWidgetMac::SetShape(gfx::NativeRegion shape) {
   NOTIMPLEMENTED();
 }
 
 void NativeWidgetMac::Close() {
   if (!bridge_)
     return;
 
+  if (delegate_->IsModal()) {
+    // Sheets can't be closed normally. This starts the sheet closing. Once the
+    // sheet has finished animating, it will call sheetDidEnd: on the parent
+    // window's delegate. Note it still needs to be asynchronous, since code
+    // calling Widget::Close() doesn't expect things to be deleted upon return.
+    [NSApp performSelector:@selector(endSheet:)
+                withObject:GetNativeWindow()
+                afterDelay:0];
+    return;
+  }
+
   // Clear the view early to suppress repaints.
   bridge_->SetRootView(NULL);
 
   NSWindow* window = GetNativeWindow();
   // Calling performClose: will momentarily highlight the close button, but
   // AppKit will reject it if there is no close button.
   SEL close_selector = ([window styleMask] & NSClosableWindowMask)
                            ? @selector(performClose:)
                            : @selector(close);
   [window performSelector:close_selector withObject:nil afterDelay:0];
@@ skipping 306 matching lines @@
 }
 
 // static
 gfx::FontList NativeWidgetPrivate::GetWindowTitleFontList() {
   NOTIMPLEMENTED();
   return gfx::FontList();
 }
 
 }  // namespace internal
 }  // namespace views