Revert 124461 - Remove the singleton instance get/delete methods from RootWindow (yay)

http://crbug.com/112131
TEST=none
Review URL: https://chromiumcodereview.appspot.com/9535025

TBR=ben@chromium.org
Review URL: https://chromiumcodereview.appspot.com/9564023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124479 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 90 insertions, 60 deletions

diff --git a/ui/aura/demo/demo_main.cc b/ui/aura/demo/demo_main.cc
index d6eccc2..48f2e8d 100644
--- a/ui/aura/demo/demo_main.cc
+++ b/ui/aura/demo/demo_main.cc
@@ -88,7 +88,7 @@ int main(int argc, char** argv) {
   MessageLoop message_loop(MessageLoop::TYPE_UI);
   ui::CompositorTestSupport::Initialize();
 
-  scoped_ptr<aura::RootWindow> root_window(new aura::RootWindow);
+  aura::RootWindow::GetInstance();
 
   // Create a hierarchy of test windows.
   DemoWindowDelegate window_delegate1(SK_ColorBLUE);
@@ -115,7 +115,7 @@ int main(int argc, char** argv) {
   window3.Show();
   window3.SetParent(&window2);
 
-  root_window->ShowRootWindow();
+  aura::RootWindow::GetInstance()->ShowRootWindow();
   MessageLoopForUI::current()->Run();
 
   ui::CompositorTestSupport::Terminate();
diff --git a/ui/aura/root_window.cc b/ui/aura/root_window.cc
index 3c3ece6..aaec097 100644
--- a/ui/aura/root_window.cc
+++ b/ui/aura/root_window.cc
@@ -83,52 +83,19 @@ bool RootWindow::hide_host_cursor_ = false;
 ////////////////////////////////////////////////////////////////////////////////
 // RootWindow, public:
 
-RootWindow::RootWindow()
-    : Window(NULL),
-      host_(aura::RootWindowHost::Create(GetInitialHostWindowBounds())),
-      ALLOW_THIS_IN_INITIALIZER_LIST(schedule_paint_factory_(this)),
-      ALLOW_THIS_IN_INITIALIZER_LIST(event_factory_(this)),
-      mouse_button_flags_(0),
-      last_cursor_(kCursorNull),
-      cursor_shown_(true),
-      ALLOW_THIS_IN_INITIALIZER_LIST(screen_(new ScreenAura(this))),
-      capture_window_(NULL),
-      mouse_pressed_handler_(NULL),
-      mouse_moved_handler_(NULL),
-      focused_window_(NULL),
-      touch_event_handler_(NULL),
-      gesture_handler_(NULL),
-      ALLOW_THIS_IN_INITIALIZER_LIST(
-          gesture_recognizer_(GestureRecognizer::Create(this))),
-      synthesize_mouse_move_(false),
-      waiting_on_compositing_end_(false),
-      draw_on_compositing_end_(false) {
-  SetName("RootWindow");
-  gfx::Screen::SetInstance(screen_);
-  last_mouse_location_ = host_->QueryMouseLocation();
-
-  ui::Compositor::Initialize(false);
-  compositor_.reset(new ui::Compositor(this, host_->GetAcceleratedWidget(),
-      host_->GetSize()));
-  DCHECK(compositor_.get());
-  compositor_->AddObserver(this);
-  Init();
+// static
+RootWindow* RootWindow::GetInstance() {
+  if (!instance_) {
+    instance_ = new RootWindow;
+    instance_->Init();
+  }
+  return instance_;
 }
 
-RootWindow::~RootWindow() {
-  compositor_->RemoveObserver(this);
-  // Make sure to destroy the compositor before terminating so that state is
-  // cleared and we don't hit asserts.
-  compositor_.reset();
-
-  // Tear down in reverse.  Frees any references held by the host.
-  host_.reset(NULL);
-
-  // An observer may have been added by an animation on the RootWindow.
-  layer()->GetAnimator()->RemoveObserver(this);
-  ui::Compositor::Terminate();
-  if (instance_ == this)
-    instance_ = NULL;
+// static
+void RootWindow::DeleteInstance() {
+  delete instance_;
+  instance_ = NULL;
 }
 
 void RootWindow::ShowRootWindow() {
@@ -478,6 +445,53 @@ void RootWindow::OnCompositingEnded(ui::Compositor*) {
 ////////////////////////////////////////////////////////////////////////////////
 // RootWindow, private:
 
+RootWindow::RootWindow()
+    : Window(NULL),
+      host_(aura::RootWindowHost::Create(GetInitialHostWindowBounds())),
+      ALLOW_THIS_IN_INITIALIZER_LIST(schedule_paint_factory_(this)),
+      ALLOW_THIS_IN_INITIALIZER_LIST(event_factory_(this)),
+      mouse_button_flags_(0),
+      last_cursor_(kCursorNull),
+      cursor_shown_(true),
+      ALLOW_THIS_IN_INITIALIZER_LIST(screen_(new ScreenAura(this))),
+      capture_window_(NULL),
+      mouse_pressed_handler_(NULL),
+      mouse_moved_handler_(NULL),
+      focused_window_(NULL),
+      touch_event_handler_(NULL),
+      gesture_handler_(NULL),
+      ALLOW_THIS_IN_INITIALIZER_LIST(
+          gesture_recognizer_(GestureRecognizer::Create(this))),
+      synthesize_mouse_move_(false),
+      waiting_on_compositing_end_(false),
+      draw_on_compositing_end_(false) {
+  SetName("RootWindow");
+  gfx::Screen::SetInstance(screen_);
+  last_mouse_location_ = host_->QueryMouseLocation();
+
+  ui::Compositor::Initialize(false);
+  compositor_.reset(new ui::Compositor(this, host_->GetAcceleratedWidget(),
+      host_->GetSize()));
+  DCHECK(compositor_.get());
+  compositor_->AddObserver(this);
+}
+
+RootWindow::~RootWindow() {
+  compositor_->RemoveObserver(this);
+  // Make sure to destroy the compositor before terminating so that state is
+  // cleared and we don't hit asserts.
+  compositor_.reset();
+
+  // Tear down in reverse.  Frees any references held by the host.
+  host_.reset(NULL);
+
+  // An observer may have been added by an animation on the RootWindow.
+  layer()->GetAnimator()->RemoveObserver(this);
+  ui::Compositor::Terminate();
+  if (instance_ == this)
+    instance_ = NULL;
+}
+
 void RootWindow::HandleMouseCaptureChanged(Window* old_capture_window) {
   if (capture_window_)
     host_->SetCapture();
diff --git a/ui/aura/root_window.h b/ui/aura/root_window.h
index 983ec87..b04857d 100644
--- a/ui/aura/root_window.h
+++ b/ui/aura/root_window.h
@@ -50,8 +50,8 @@ class AURA_EXPORT RootWindow : public ui::CompositorDelegate,
                                public internal::FocusManager,
                                public ui::LayerAnimationObserver {
  public:
-  RootWindow();
-  virtual ~RootWindow();
+  static RootWindow* GetInstance();
+  static void DeleteInstance();
 
   static void set_use_fullscreen_host_window(bool use_fullscreen) {
     use_fullscreen_host_window_ = use_fullscreen;
@@ -197,6 +197,9 @@ class AURA_EXPORT RootWindow : public ui::CompositorDelegate,
  private:
   friend class Window;
 
+  RootWindow();
+  virtual ~RootWindow();
+
   // Called whenever the mouse moves, tracks the current |mouse_moved_handler_|,
   // sending exited and entered events as its value changes.
   void HandleMouseMoved(const MouseEvent& event, Window* target);
diff --git a/ui/aura/root_window_host_linux.cc b/ui/aura/root_window_host_linux.cc
index a6c4e5a..342e114 100644
--- a/ui/aura/root_window_host_linux.cc
+++ b/ui/aura/root_window_host_linux.cc
@@ -305,6 +305,8 @@ RootWindowHostLinux::RootWindowHostLinux(const gfx::Rect& bounds)
   if (base::MessagePumpForUI::HasXInput2())
     ui::TouchFactory::GetInstance()->SetupXI2ForXWindow(xwindow_);
 
+  MessageLoopForUI::current()->AddDestructionObserver(this);
+
   // Initialize invisible cursor.
   char nodata[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
   XColor black;
@@ -326,6 +328,8 @@ RootWindowHostLinux::~RootWindowHostLinux() {
   ui::GetXCursor(ui::kCursorClearXCursorCache);
 
   XFreeCursor(xdisplay_, invisible_cursor_);
+
+  MessageLoopForUI::current()->RemoveDestructionObserver(this);
 }
 
 base::MessagePumpDispatcher::DispatchStatus RootWindowHostLinux::Dispatch(
@@ -620,6 +624,10 @@ void RootWindowHostLinux::PostNativeEvent(
   XSendEvent(xdisplay_, xwindow_, False, 0, &xevent);
 }
 
+void RootWindowHostLinux::WillDestroyCurrentMessageLoop() {
+  aura::RootWindow::DeleteInstance();
+}
+
 bool RootWindowHostLinux::IsWindowManagerPresent() {
   // Per ICCCM 2.8, "Manager Selections", window managers should take ownership
   // of WM_Sn selections (where n is a screen number).
diff --git a/ui/aura/root_window_host_linux.h b/ui/aura/root_window_host_linux.h
index 2ad9fe7..0d05b7b 100644
--- a/ui/aura/root_window_host_linux.h
+++ b/ui/aura/root_window_host_linux.h
@@ -17,7 +17,8 @@
 
 namespace aura {
 
-class RootWindowHostLinux : public RootWindowHost {
+class RootWindowHostLinux : public RootWindowHost,
+                            public MessageLoop::DestructionObserver {
  public:
   explicit RootWindowHostLinux(const gfx::Rect& bounds);
   virtual ~RootWindowHostLinux();
@@ -44,6 +45,9 @@ class RootWindowHostLinux : public RootWindowHost {
   virtual void MoveCursorTo(const gfx::Point& location) OVERRIDE;
   virtual void PostNativeEvent(const base::NativeEvent& event) OVERRIDE;
 
+  // MessageLoop::DestructionObserver Overrides.
+  virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
+
   // Returns true if there's an X window manager present... in most cases.  Some
   // window managers (notably, ion3) don't implement enough of ICCCM for us to
   // detect that they're there.
diff --git a/ui/aura/test/aura_test_base.cc b/ui/aura/test/aura_test_base.cc
index a7399a8..5747b38 100644
--- a/ui/aura/test/aura_test_base.cc
+++ b/ui/aura/test/aura_test_base.cc
@@ -10,33 +10,34 @@
 namespace aura {
 namespace test {
 
-AuraTestBase::AuraTestBase() {
+AuraTestBase::AuraTestBase() : root_window_(RootWindow::GetInstance()) {
+  helper_.InitRootWindow(root_window_);
 }
 
 AuraTestBase::~AuraTestBase() {
+  // Flush the message loop because we have pending release tasks
+  // and these tasks if un-executed would upset Valgrind.
+  helper_.RunAllPendingInMessageLoop(root_window_);
+
+  // Ensure that we don't use the previously-allocated static RootWindow object
+  // later -- on Linux, it holds a reference to our message loop's X connection.
+  RootWindow::DeleteInstance();
 }
 
 void AuraTestBase::SetUp() {
   testing::Test::SetUp();
-  root_window_.reset(new aura::RootWindow);
-  helper_.InitRootWindow(root_window());
   helper_.SetUp();
   stacking_client_.reset(new TestStackingClient(root_window()));
 }
 
 void AuraTestBase::TearDown() {
-  // Flush the message loop because we have pending release tasks
-  // and these tasks if un-executed would upset Valgrind.
-  RunAllPendingInMessageLoop();
-
   stacking_client_.reset();
   helper_.TearDown();
-  root_window_.reset();
   testing::Test::TearDown();
 }
 
 void AuraTestBase::RunAllPendingInMessageLoop() {
-  helper_.RunAllPendingInMessageLoop(root_window());
+  helper_.RunAllPendingInMessageLoop(root_window_);
 }
 
 }  // namespace test
diff --git a/ui/aura/test/aura_test_base.h b/ui/aura/test/aura_test_base.h
index 14bd3f9..7b2a134 100644
--- a/ui/aura/test/aura_test_base.h
+++ b/ui/aura/test/aura_test_base.h
@@ -30,11 +30,11 @@ class AuraTestBase : public testing::Test {
  protected:
   void RunAllPendingInMessageLoop();
 
-  RootWindow* root_window() { return root_window_.get(); }
+  RootWindow* root_window() { return root_window_; }
 
  private:
   AuraTestHelper helper_;
-  scoped_ptr<RootWindow> root_window_;
+  RootWindow* root_window_;
   scoped_ptr<TestStackingClient> stacking_client_;
 
   DISALLOW_COPY_AND_ASSIGN(AuraTestBase);