Remove code for losing activation when child window activated.

ui/views/win/hwnd_message_handler.cc

 // Copyright (c) 2012 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/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 #include <tchar.h>
@@ skipping 1501 matching lines @@
   // location is another window on the same thread, that window gets a
   // WM_MOUSEACTIVATE message and ends up activating itself, which is not
   // correct. We workaround this by setting a property on the window at the
   // current cursor location. We check for this property in our
   // WM_MOUSEACTIVATE handler and don't activate the window if the property is
   // set.
   if (::GetProp(hwnd(), ui::kIgnoreTouchMouseActivateForWindow)) {
     ::RemoveProp(hwnd(), ui::kIgnoreTouchMouseActivateForWindow);
     return MA_NOACTIVATE;
   }
-  // A child window activation should be treated as if we lost activation.
-  POINT cursor_pos = {0};
-  ::GetCursorPos(&cursor_pos);
-  ::ScreenToClient(hwnd(), &cursor_pos);
-  // The code below exists for child windows like NPAPI plugins etc which need
-  // to be activated whenever we receive a WM_MOUSEACTIVATE message. Don't put
-  // transparent child windows in this bucket as they are not supposed to grab
-  // activation.
-  // TODO(ananta)
-  // Get rid of this code when we deprecate NPAPI plugins.
-  HWND child = ::RealChildWindowFromPoint(hwnd(), cursor_pos);
-  if (::IsWindow(child) && child != hwnd() && ::IsWindowVisible(child) &&
-      !(::GetWindowLong(child, GWL_EXSTYLE) & WS_EX_TRANSPARENT))
-    PostProcessActivateMessage(WA_INACTIVE, false);
 
   // TODO(beng): resolve this with the GetWindowLong() check on the subsequent
   //             line.
   if (delegate_->IsWidgetWindow()) {
     if (delegate_->CanActivate())
       return MA_ACTIVATE;
     if (delegate_->WantsMouseEventsWhenInactive())
       return MA_NOACTIVATE;
     return MA_NOACTIVATEANDEAT;
   }
@@ skipping 1026 matching lines @@
 
     default:
       left_button_down_on_caption_ = false;
       break;
   }
   return handled;
 }
 
 
 }  // namespace views