Attempting to reland the Overview Button Change.

ash/system/status_area_widget.cc

Index: ash/system/status_area_widget.cc
diff --git a/ash/system/status_area_widget.cc b/ash/system/status_area_widget.cc
index 454f3ca43778cfc17b785996fde6fdcf7eff2978..55fd8dc46120fb5ff7aafa9f10e77c37249994a6 100644
--- a/ash/system/status_area_widget.cc
+++ b/ash/system/status_area_widget.cc
@@ -11,6 +11,7 @@
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/bluetooth/bluetooth_observer.h"
+#include "ash/system/overview/overview_button_tray.h"
 #include "ash/system/status_area_widget_delegate.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
@@ -33,6 +34,7 @@ const char StatusAreaWidget::kNativeViewName[] = "StatusAreaWidget";
 
 StatusAreaWidget::StatusAreaWidget(aura::Window* status_container)
     : status_area_widget_delegate_(new internal::StatusAreaWidgetDelegate),
+      overview_button_tray_(NULL),
       system_tray_(NULL),
       web_notification_tray_(NULL),
 #if defined(OS_CHROMEOS)
@@ -55,26 +57,25 @@ StatusAreaWidget::~StatusAreaWidget() {
 }
 
 void StatusAreaWidget::CreateTrayViews() {
+  AddOverviewButtonTray();
   AddSystemTray();
   AddWebNotificationTray();
 #if defined(OS_CHROMEOS)
   AddLogoutButtonTray();
   AddVirtualKeyboardTray();
 #endif
+
   SystemTrayDelegate* delegate =
       ash::Shell::GetInstance()->system_tray_delegate();
   DCHECK(delegate);
   // Initialize after all trays have been created.
-  if (system_tray_)
-    system_tray_->InitializeTrayItems(delegate);
-  if (web_notification_tray_)
-    web_notification_tray_->Initialize();
+  system_tray_->InitializeTrayItems(delegate);
+  web_notification_tray_->Initialize();
 #if defined(OS_CHROMEOS)
-  if (logout_button_tray_)
-    logout_button_tray_->Initialize();
-  if (virtual_keyboard_tray_)
-    virtual_keyboard_tray_->Initialize();
+  logout_button_tray_->Initialize();
+  virtual_keyboard_tray_->Initialize();
 #endif
+  overview_button_tray_->Initialize();
   UpdateAfterLoginStatusChange(delegate->GetUserLoginStatus());
 }
 
@@ -92,6 +93,8 @@ void StatusAreaWidget::Shutdown() {
   delete logout_button_tray_;
   logout_button_tray_ = NULL;
 #endif
+  delete overview_button_tray_;
+  overview_button_tray_ = NULL;
 }
 
 bool StatusAreaWidget::ShouldShowShelf() const {
@@ -106,8 +109,8 @@ bool StatusAreaWidget::ShouldShowShelf() const {
   // If the shelf is currently visible, don't hide the shelf if the mouse
   // is in any of the notification bubbles.
   return (system_tray_ && system_tray_->IsMouseInNotificationBubble()) ||
-        (web_notification_tray_ &&
-         web_notification_tray_->IsMouseInNotificationBubble());
+         (web_notification_tray_ &&
+          web_notification_tray_->IsMouseInNotificationBubble());
 }
 
 bool StatusAreaWidget::IsMessageBubbleShown() const {
@@ -144,6 +147,11 @@ void StatusAreaWidget::AddVirtualKeyboardTray() {
 }
 #endif
 
+void StatusAreaWidget::AddOverviewButtonTray() {
+  overview_button_tray_ = new OverviewButtonTray(this);
+  status_area_widget_delegate_->AddTray(overview_button_tray_);
+}
+
 void StatusAreaWidget::SetShelfAlignment(ShelfAlignment alignment) {
   status_area_widget_delegate_->set_alignment(alignment);
   if (system_tray_)
@@ -156,6 +164,8 @@ void StatusAreaWidget::SetShelfAlignment(ShelfAlignment alignment) {
   if (virtual_keyboard_tray_)
     virtual_keyboard_tray_->SetShelfAlignment(alignment);
 #endif
+  if (overview_button_tray_)
+    overview_button_tray_->SetShelfAlignment(alignment);
   status_area_widget_delegate_->UpdateLayout();
 }