Fixing problem with incomplete browser windows showing up after task manager was used

chrome/browser/ui/views/task_manager_view.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 "chrome/browser/task_manager/task_manager.h"
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/metrics/stats_table.h"
 #include "base/prefs/pref_service.h"
@@ skipping 26 matching lines @@
 #include "ui/views/controls/menu/menu_model_adapter.h"
 #include "ui/views/controls/menu/menu_runner.h"
 #include "ui/views/controls/table/table_grouper.h"
 #include "ui/views/controls/table/table_view.h"
 #include "ui/views/controls/table/table_view_observer.h"
 #include "ui/views/controls/table/table_view_row_background_painter.h"
 #include "ui/views/layout/layout_constants.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/dialog_delegate.h"
 
+#if defined(USE_ASH)
+#include "ash/wm/window_util.h"
+#endif
+
 #if defined(OS_WIN)
 #include "win8/util/win8_util.h"
 #endif
 
 // Yellow highlight used when highlighting background resources.
 static const SkColor kBackgroundResourceHighlight =
     SkColorSetRGB(0xff, 0xf1, 0xcd);
 
 namespace {
 
@@ skipping 467 matching lines @@
   return gfx::Size(460, 270);
 }
 
 // static
 void TaskManagerView::Show(bool highlight_background_resources,
                            Browser* browser) {
 #if defined(OS_WIN)
   // In Windows Metro it's not good to open this native window.
   DCHECK(!win8::IsSingleWindowMetroMode());
 #endif
-  const chrome::HostDesktopType desktop_type = browser->host_desktop_type();
+  const chrome::HostDesktopType desktop_type =
+      browser ? browser->host_desktop_type() : chrome::HOST_DESKTOP_TYPE_ASH;

[sky, 2013/03/20 23:52:08]

Document why browser == NULL is treated as ASH.

[Mr4D (OOO till 08-26), 2013/03/21 00:20:10]

Done.

 
   if (instance_) {
     if (instance_->highlight_background_resources_ !=
         highlight_background_resources ||
         instance_->desktop_type_ != desktop_type) {
       instance_->GetWidget()->Close();
     } else {
       // If there's a Task manager window open already, just activate it.
       instance_->GetWidget()->Activate();
       return;
     }
   }
   instance_ = new TaskManagerView(highlight_background_resources, desktop_type);
-  DialogDelegateView::CreateDialogWidget(instance_,
-      browser->window()->GetNativeWindow(), NULL);
+  aura::Window* window = browser ? browser->window()->GetNativeWindow() : NULL;
+#if defined(USE_ASH)
+  if (!window)
+    window = ash::wm::GetActiveWindow();
+#endif
+  DialogDelegateView::CreateDialogWidget(instance_, window, NULL);

[sky, 2013/03/20 23:52:08]

Can you verify this does the right thing if window is NULL. I have a feeling it
hits a DCHECK, but I could be wrong.

[Mr4D (OOO till 08-26), 2013/03/21 00:20:10]

I did already before checking in and it did not. 

[sky, 2013/03/21 00:25:55]

So then don't you need to deal with it being null here? By null here I mean 559
returning null.

[Mr4D (OOO till 08-26), 2013/03/21 00:29:30]

You misunderstood - It did not cause any problems (hit DCHECK or anything). I
was intently passing in (instance_, NULL, NULL) and everything worked.

   instance_->InitAlwaysOnTopState();
   instance_->model_->StartUpdating();
   instance_->GetWidget()->Show();
 
   // Set the initial focus to the list of tasks.
   views::FocusManager* focus_manager = instance_->GetFocusManager();
   if (focus_manager)
     focus_manager->SetFocusedView(instance_->tab_table_);
 }
 
@@ skipping 196 matching lines @@
       g_browser_process->local_state()->GetDictionary(GetWindowName().c_str());
   return dictionary &&
       dictionary->GetBoolean("always_on_top", always_on_top) && always_on_top;
 }
 
 }  // namespace
 
 namespace chrome {
 
 // Declared in browser_dialogs.h so others don't need to depend on our header.
-void ShowTaskManager(Browser* browser) {
-  TaskManagerView::Show(false, browser);
-}
-
-void ShowBackgroundPages(Browser* browser) {
-  TaskManagerView::Show(true, browser);
+void ShowTaskManager(Browser* browser, bool highlight_background_resources) {
+  TaskManagerView::Show(highlight_background_resources, browser);
 }
 
 }  // namespace chrome