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. Support returning Widgets that are parented to the NSWindow, except:
+    // - Ignore requests for children of an NSView that is not a contentView.
+    // - We do not add a Widget for |native_view| to |children| (there is none).
+    if ([[native_view window] contentView] != native_view)
+      return;
+
+    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).
   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());
 
+  // When the NSWindow *is* a Widget, only consider child_windows(). I.e. do not
+  // look through -[NSWindow childWindows] as done for the (!bridge) case above.
+  // -childWindows does not support hidden windows, and anything in there which
+  // is not in child_windows() would have been added by AppKit.
   for (BridgedNativeWidget* child : bridge->child_windows())
     GetAllChildWidgets(child->ns_view(), children);
 }
 
 // static
 void NativeWidgetPrivate::GetAllOwnedWidgets(gfx::NativeView native_view,
                                              Widget::Widgets* owned) {
   NOTIMPLEMENTED();
 }
 
@@ skipping 48 matching lines @@
   [[ViewsNSWindowCloseAnimator alloc] initWithWindow:window];
 }
 
 - (void)animationDidEnd:(NSAnimation*)animation {
   [window_ close];
   [animation_ setDelegate:nil];
   [self release];
 }
 
 @end