wm: Make _NET_ACTIVE_WINDOW contain transient windows.

src/platform/window_manager/layout_manager.cc

 // Copyright (c) 2009 The Chromium OS 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 "window_manager/layout_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <tr1/memory>
 extern "C" {
@@ skipping 270 matching lines @@
       if (win->transient_for_xid() != None) {
         ToplevelWindow* toplevel_owner =
             GetToplevelWindowByXid(win->transient_for_xid());
         if (toplevel_owner) {
           transient_to_toplevel_[win->xid()] = toplevel_owner;
           toplevel_owner->AddTransientWindow(win);
 
           if (mode_ == MODE_ACTIVE &&
               active_toplevel_ != NULL &&
               active_toplevel_->IsWindowOrTransientFocused()) {
-            // The _NET_ACTIVE_WINDOW property should already refer to
-            // 'active_toplevel_', since it previously had the focus.
             active_toplevel_->TakeFocus(wm_->GetCurrentTimeFromServer());
           }
           break;
         } else {
           LOG(WARNING) << "Ignoring " << win->xid_str()
                        << "'s WM_TRANSIENT_FOR hint of "
                        << XidStr(win->transient_for_xid())
                        << ", which isn't a toplevel window";
           // Continue on and treat the transient as a toplevel window.
         }
@@ skipping 182 matching lines @@
   ToplevelWindow* toplevel = GetToplevelWindowOwningTransientWindow(*win);
   if (!toplevel)
     toplevel = GetToplevelWindowByWindow(*win);
 
   // If this is neither a toplevel nor transient window, we don't care
   // about the focus change.
   if (!toplevel)
     return false;
   toplevel->HandleFocusChange(win, focus_in);
 
-  // When a transient window gets the focus, we say that its owner is the
-  // "active" window (in the _NET_ACTIVE_WINDOW sense).
+  // Announce that the new window is the "active" window (in the
+  // _NET_ACTIVE_WINDOW sense), regardless of whether it's a toplevel
+  // window or a transient.
   if (focus_in)
-    wm_->SetActiveWindowProperty(toplevel->win()->xid());
+    wm_->SetActiveWindowProperty(win->xid());
 
   return true;
 }
 
 bool LayoutManager::HandleChromeMessage(const WmIpc::Message& msg) {
   switch (msg.type()) {
     case WmIpc::Message::WM_MOVE_FLOATING_TAB: {
       XWindow xid = msg.param(0);
       int x = msg.param(1);
       int y = msg.param(2);
@@ skipping 1186 matching lines @@
 }
 
 void LayoutManager::SendDeleteRequestToActiveWindow() {
   // TODO: If there's a focused transient window, the message should get
   // sent to it instead.
   if (mode_ == MODE_ACTIVE && active_toplevel_)
     active_toplevel_->win()->SendDeleteRequest(wm_->GetCurrentTimeFromServer());
 }
 
 }  // namespace chromeos