Added notion of currently active app / browser

ui/views/widget/native_widget_aura.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/widget/native_widget_aura.h"
 
 #include "base/bind.h"
 #include "base/string_util.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/aura/client/activation_client.h"
@@ skipping 755 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeWidgetAura, aura::ActivationDelegate implementation:
 
 bool NativeWidgetAura::ShouldActivate(aura::Event* event) {
   return can_activate_ && delegate_->CanActivate();
 }
 
 void NativeWidgetAura::OnActivated() {
-  GetWidget()->GetFocusManager()->RestoreFocusedView();
+  if (GetWidget()->HasFocusManager())
+    GetWidget()->GetFocusManager()->RestoreFocusedView();
   delegate_->OnNativeWidgetActivationChanged(true);
   if (IsVisible() && GetWidget()->non_client_view())
     GetWidget()->non_client_view()->SchedulePaint();
 }
 
 void NativeWidgetAura::OnLostActive() {
-  GetWidget()->GetFocusManager()->StoreFocusedView();
+  if (GetWidget()->HasFocusManager())
+    GetWidget()->GetFocusManager()->StoreFocusedView();
   delegate_->OnNativeWidgetActivationChanged(false);
   if (IsVisible() && GetWidget()->non_client_view())
     GetWidget()->non_client_view()->SchedulePaint();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeWidgetAura, aura::WindowDragDropDelegate implementation:
 
 void NativeWidgetAura::OnDragEntered(const aura::DropTargetEvent& event) {
   DCHECK(drop_helper_.get() != NULL);
@@ skipping 124 matching lines @@
   }
 }
 
 // static
 bool NativeWidgetPrivate::IsMouseButtonDown() {
   return aura::Env::GetInstance()->is_mouse_button_down();
 }
 
 }  // namespace internal
 }  // namespace views