desktopCapture: minimized window shouldn't be treated as on-top on Win10

webrtc/modules/desktop_capture/cropping_window_capturer_win.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 24 matching lines @@
   DWORD selected_window_process_id;
   DesktopRect selected_window_rect;
 };
 
 // The function is called during EnumWindow for every window enumerated and is
 // responsible for verifying if the selected window is on top.
 BOOL CALLBACK TopWindowVerifier(HWND hwnd, LPARAM param) {
   TopWindowVerifierContext* context =
       reinterpret_cast<TopWindowVerifierContext*>(param);
 
-  if (hwnd == context->selected_window) {
-    context->is_top_window = true;
-    return FALSE;
-  }
-
   // Ignore the excluded window.
   if (hwnd == context->excluded_window) {
     return TRUE;
   }
 
   // Ignore hidden or minimized window.
   if (IsIconic(hwnd) || !IsWindowVisible(hwnd)) {
     return TRUE;
   }
 
+  if (hwnd == context->selected_window) {

[Hzj_jie, 2017/08/07 19:28:29]

After this change, unnecessary checks for other windows will be performed. A
simple approach can be adding
====================
if (IsIconic(selected_window_) || !IsWindowVisible(selected_window_)) {
  return false;
}
====================
in ShouldUseScreenCapturer() around line 129.

P.S. Several more suggestions:
1. Add a RTC_DCHECK_NE in the contructor of TopWindowVerifierContext to ensure
excluded_window != selected_window.
2. Move initialization of selected_window_rect also into the contructor.
3. Remove selected_window_process_id.
4. const selected_window / excluded_window / selected_window_rect.

Since you are touching this file, if you are not interested in applying these
changes, you can add TODOs in TopWindowVerifierContext. Thank you.

+    context->is_top_window = true;
+    return FALSE;
+  }
   // Ignore descendant/owned windows since we want to capture them.
   // This check does not work for tooltips and context menus. Drop down menus
   // and popup windows are fine.
   if (GetAncestor(hwnd, GA_ROOTOWNER) == context->selected_window) {
     return TRUE;
   }
 
   // If |hwnd| has no title and belongs to the same process, assume it's a
   // tooltip or context menu from the selected window and ignore it.
   const size_t kTitleLength = 32;
@@ skipping 140 matching lines @@
 }  // namespace
 
 // static
 std::unique_ptr<DesktopCapturer> CroppingWindowCapturer::CreateCapturer(
     const DesktopCaptureOptions& options) {
   return std::unique_ptr<DesktopCapturer>(
       new CroppingWindowCapturerWin(options));
 }
 
 }  // namespace webrtc