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

chrome/browser/ui/views/task_manager_view.cc

Index: chrome/browser/ui/views/task_manager_view.cc
diff --git a/chrome/browser/ui/views/task_manager_view.cc b/chrome/browser/ui/views/task_manager_view.cc
index f49a4a2069e18dc2fdf8b35c920cb69bd9b2357f..ad3829517cd97e7cdb219f133d377b68ce7c36eb 100644
--- a/chrome/browser/ui/views/task_manager_view.cc
+++ b/chrome/browser/ui/views/task_manager_view.cc
@@ -44,6 +44,10 @@
 #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
@@ -531,7 +535,8 @@ void TaskManagerView::Show(bool highlight_background_resources,
   // 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_ !=
@@ -545,8 +550,12 @@ void TaskManagerView::Show(bool highlight_background_resources,
     }
   }
   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();
@@ -763,12 +772,8 @@ bool TaskManagerView::GetSavedAlwaysOnTopState(bool* always_on_top) const {
 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