MacViews: Fix Widget::GetAllChildWidgets(gfx::NativeView) for non-Widgets.

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 <utility>
 
@@ skipping 671 matching lines @@
                              [bridge->parent()->GetNSWindow() contentView])
                        : nullptr;
   return ancestor ? ancestor : bridge->native_widget_mac();
 }
 
 // static
 void NativeWidgetPrivate::GetAllChildWidgets(gfx::NativeView native_view,
                                              Widget::Widgets* children) {
   BridgedNativeWidget* bridge =
       NativeWidgetMac::GetBridgeForNativeWindow([native_view window]);
-  if (!bridge)
+  if (!bridge) {
+    // The NSWindow is not itself a views::Widget, but it may have children that
+    // are. Note we assume we don't care about children of Widgets that are not
+    // themselves a Widget (those are skipped by this logic).

[karandeepb, 2016/11/29 05:28:42]

It's not clear to me what this comment means- "Note we assume we don't care
about children of Widgets that are not themselves a Widget (those are skipped by
this logic)."

[tapted, 2016/11/29 05:51:42]

Moved it down to the other for loop and reworded.

[karandeepb, 2016/11/29 06:00:20]

Acknowledged.

+    for (NSWindow* native_child in [[native_view window] childWindows])
+      GetAllChildWidgets([native_child contentView], children);
     return;
+  }
 
   // If |native_view| is a subview of the contentView, it will share an
   // NSWindow, but will itself be a native child of the Widget. That is, adding
   // bridge->..->GetWidget() to |children| would be adding the _parent_ of
   // |native_view|, not the Widget for |native_view|. |native_view| doesn't have
   // a corresponding Widget of its own in this case (and so can't have Widget
   // children of its own on Mac).

[karandeepb, 2016/11/29 05:28:42]

Should we not do the same for this case?

[tapted, 2016/11/29 05:51:42]

Done.

[karandeepb, 2016/11/29 06:00:20]

Actually I meant iterating over the child windows of [[native_view window]
childWindows] for this case as well, not the other way round. But yeah it's not
clear if for this case, [[native_view window] childWindows] can be considered to
be in the hierarchy of native_view, probably not. 

[tapted, 2016/11/29 06:06:11]

Ah, yep. GetBridgeForNativeWindow uses the NSWindow delegate -- there can be
only one per window, so it might be confusing. We can always revisit if we find
a use-case for it though.

   if (bridge->ns_view() != native_view)
     return;
 
   // Code expects widget for |native_view| to be added to |children|.
   if (bridge->native_widget_mac()->GetWidget())
     children->insert(bridge->native_widget_mac()->GetWidget());
 
   for (BridgedNativeWidget* child : bridge->child_windows())
     GetAllChildWidgets(child->ns_view(), children);
 }
@@ skipping 55 matching lines @@
   [[ViewsNSWindowCloseAnimator alloc] initWithWindow:window];
 }
 
 - (void)animationDidEnd:(NSAnimation*)animation {
   [window_ close];
   [animation_ setDelegate:nil];
   [self release];
 }
 
 @end