Do not filter the picker window with Aura.

chrome/browser/ui/views/desktop_media_picker_views.cc

 // Copyright 2013 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 "chrome/browser/media/desktop_media_picker.h"
 
 #include "base/callback.h"
 #include "chrome/browser/media/desktop_media_list.h"
 #include "chrome/browser/media/desktop_media_list_observer.h"
 #include "chrome/browser/ui/ash/ash_util.h"
@@ skipping 528 matching lines @@
   // web contents. Otherwise, a new dialog widget inside |parent_window| will be
   // created for the picker. Note that |parent_window| may also be NULL if
   // parent web contents is not set. In this case the picker will be parented
   // by a root window.
   views::Widget* widget = NULL;
   if (parent_web_contents)
     widget = CreateWebModalDialogViews(this, parent_web_contents);
   else
     widget = DialogDelegate::CreateDialogWidget(this, context, parent_window);
 
-  // DesktopMediaList needs to know the ID of the picker window which
-  // matches the ID it gets from the OS. Depending on the OS and configuration
-  // we get this ID differently.
-  content::DesktopMediaID::Id dialog_window_id = 0;
-#if defined(USE_ASH)
-  if (chrome::IsNativeWindowInAsh(widget->GetNativeWindow())) {
-    dialog_window_id = content::DesktopMediaID::RegisterAuraWindow(
-        widget->GetNativeWindow()).id;
-    DCHECK_NE(dialog_window_id, 0);
-  }
-#endif
-  if (dialog_window_id == 0) {
-    dialog_window_id = AcceleratedWidgetToDesktopMediaId(
-        widget->GetNativeWindow()->GetHost()->GetAcceleratedWidget());
-  }
-
-  list_view_->StartUpdating(dialog_window_id);
+  // The picker window is embedded in the parent window and does not have its
+  // own native window with Aura. So we do not filter any window.

[Sergey Ulanov, 2014/06/13 17:38:41]

Actually it's not always the case. We still have a separate dialog window in
some cases - see line 547. 
If CreateWebModalDialogView() is used to create the dialog, then we don't want
to filter it, but we still want filtering when the dialog is created using
DialogDelegate::CreateDialogWidget()

[jiayl, 2014/06/13 17:54:54]

But I tested both the desktopCapture example extension (i.e. CreateDialogWidget)
code path and the tab delegated code path (i.e. createWebModalDialogViews), the
picker dialog is not listed in the picker without filtering.

+  list_view_->StartUpdating(0);
 
   if (parent_web_contents) {
     web_modal::WebContentsModalDialogManager* manager =
         web_modal::WebContentsModalDialogManager::FromWebContents(
             parent_web_contents);
     manager->ShowModalDialog(widget->GetNativeView());
   } else {
     widget->Show();
   }
 }
@@ skipping 113 matching lines @@
       base::Bind(callback_, source));
   callback_.Reset();
 }
 
 }  // namespace
 
 // static
 scoped_ptr<DesktopMediaPicker> DesktopMediaPicker::Create() {
   return scoped_ptr<DesktopMediaPicker>(new DesktopMediaPickerViews());
 }