Bug Fix: Desktop Capture Picker Not Modal

chrome/browser/extensions/api/desktop_capture/desktop_capture_base.cc

 // Copyright 2015 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/extensions/api/desktop_capture/desktop_capture_base.h"
 
 #include <tuple>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/media/webrtc/desktop_media_list_ash.h"
 #include "chrome/browser/media/webrtc/desktop_streams_registry.h"
 #include "chrome/browser/media/webrtc/media_capture_devices_dispatcher.h"
 #include "chrome/browser/media/webrtc/native_desktop_media_list.h"
 #include "chrome/browser/media/webrtc/tab_desktop_media_list.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "components/version_info/version_info.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/common/switches.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "third_party/webrtc/modules/desktop_capture/screen_capturer.h"
 #include "third_party/webrtc/modules/desktop_capture/window_capturer.h"
 
 namespace extensions {
@@ skipping 79 matching lines @@
         request_audio = !has_flag;
         break;
     }
   }
 
   if (!show_screens && !show_windows && !show_tabs) {
     error_ = kEmptySourcesListError;
     return false;
   }
 
-  const gfx::NativeWindow parent_window =
-      web_contents->GetTopLevelNativeWindow();
+  gfx::NativeWindow parent_window = web_contents->GetTopLevelNativeWindow();
+  if (!parent_window) {
+    Browser* target_browser = chrome::FindAnyBrowser(

[Sergey Ulanov, 2016/10/24 21:37:31]

I'm not sure this is the right thing to do. This basically picks a random
window, which may be confusing in some cases, as the result may be a window that
is not the one the user currently interracts with (e.g. you click extension
button in one browser, dialog pops up in another one). I think it's better to
use the last active tabbed window for that profile.

The video in the bug shows extension button clicked. Why
GetTopLevelNativeWindow() doesn't return correct window in that case?

[qiangchen, 2016/10/24 22:18:39]

The chooseDesktopMedia is from the background Javascript of the extension, and
logically, the extension is not part of the tab it is interacting with, and
further the extension seems not to belong to any browser window. So
|web_contents->getTopLevelWindow| return null.

+        Profile::FromBrowserContext(web_contents->GetBrowserContext()), false);
+
+    content::WebContents* target_contents =

[Sergey Ulanov, 2016/10/24 21:37:31]

I don't think you need to get target content. Instead you can use 
target_browser->window()->GetNativeWindow() to get the NativeWindow for the
browser.

[qiangchen, 2016/10/24 22:18:39]

Done.

+        target_browser->tab_strip_model()->GetActiveWebContents();

[Sergey Ulanov, 2016/10/24 21:37:31]

Need to check that target_browser isn't nullptr.

[qiangchen, 2016/10/24 22:18:40]

Done.

+
+    parent_window = target_contents->GetTopLevelNativeWindow();
+  }
   std::unique_ptr<DesktopMediaList> screen_list;
   std::unique_ptr<DesktopMediaList> window_list;
   std::unique_ptr<DesktopMediaList> tab_list;
   if (g_picker_factory) {
     PickerFactory::MediaListArray media_lists =
         g_picker_factory->CreateModel(show_screens, show_windows, show_tabs,
                                       request_audio);
     screen_list = std::move(media_lists[0]);
     window_list = std::move(media_lists[1]);
     tab_list = std::move(media_lists[2]);
@@ skipping 142 matching lines @@
 
 void DesktopCaptureRequestsRegistry::CancelRequest(int process_id,
                                                    int request_id) {
   RequestsMap::iterator it = requests_.find(RequestId(process_id, request_id));
   if (it != requests_.end())
     it->second->Cancel();
 }
 
 
 }  // namespace extensions