aura: Add X11 host window management.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index b0176688f775286b0e3ee3a46b9bc944ad689b86..faea131d799e9fd8fb6f46cb63ec34e7ecac1dd5 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -15,6 +15,7 @@
 #include "ash/drag_drop/drag_drop_controller.h"
 #include "ash/focus_cycler.h"
 #include "ash/high_contrast/high_contrast_controller.h"
+#include "ash/hostwm/host_window_manager.h"
 #include "ash/launcher/launcher.h"
 #include "ash/magnifier/magnification_controller.h"
 #include "ash/display/display_controller.h"
@@ -101,6 +102,10 @@
 #include "ui/aura/dispatcher_linux.h"
 #endif  // defined(OS_CHROMEOS)
 
+#if defined(USE_X11)
+#include "ui/aura/hostwm/host_window_manager_x11.h"
+#endif
+
 namespace ash {
 
 namespace {
@@ -191,6 +196,13 @@ Shell::Shell(ShellDelegate* delegate)
 }
 
 Shell::~Shell() {
+#if defined(USE_X11)
+  x11_host_window_manager_.reset();
+#endif
+
+  // This holds a pointer to the host_window_manager_ that we own.
+  host_window_manager_.reset();
+
   views::FocusManagerFactory::Install(NULL);
 
   // Remove the focus from any window. This will prevent overhead and side
@@ -357,6 +369,15 @@ std::vector<aura::Window*> Shell::GetAllContainers(int container_id) {
 }
 
 void Shell::Init() {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+        switches::kAuraEnableHostWindowManagement)) {
+    host_window_manager_.reset(new internal::HostWindowManager);
+#if defined(USE_X11)
+    x11_host_window_manager_.reset(new aura::HostWindowManagerX11(
+        host_window_manager_.get()));
+#endif
+  }
+
   // Install the custom factory first so that views::FocusManagers for Tray,
   // Launcher, and WallPaper could be created by the factory.
   views::FocusManagerFactory::Install(new AshFocusManagerFactory);
@@ -497,6 +518,11 @@ void Shell::Init() {
 
   if (initially_hide_cursor_)
     aura::Env::GetInstance()->cursor_manager()->ShowCursor(false);
+
+#if defined(USE_X11)
+  if (x11_host_window_manager_.get())
+    x11_host_window_manager_->Init();
+#endif
 }
 
 void Shell::AddEnvEventFilter(aura::EventFilter* filter) {