MonitorManager to manage multiple monitors.

ui/aura/root_window.cc

Index: ui/aura/root_window.cc
diff --git a/ui/aura/root_window.cc b/ui/aura/root_window.cc
index cc0281965fc4ced31c26ec14f9479b02d9dc71e4..741bff11024d7d7611baf84afd2d187d3cb68616 100644
--- a/ui/aura/root_window.cc
+++ b/ui/aura/root_window.cc
@@ -16,12 +16,14 @@
 #include "ui/aura/aura_switches.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/env.h"
-#include "ui/aura/root_window_host.h"
-#include "ui/aura/root_window_observer.h"
 #include "ui/aura/event.h"
 #include "ui/aura/event_filter.h"
 #include "ui/aura/focus_manager.h"
 #include "ui/aura/gestures/gesture_recognizer.h"
+#include "ui/aura/monitor.h"
+#include "ui/aura/monitor_manager.h"
+#include "ui/aura/root_window_host.h"
+#include "ui/aura/root_window_observer.h"
 #include "ui/aura/screen_aura.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
@@ -91,7 +93,6 @@ RootWindow::RootWindow()
       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),
@@ -104,7 +105,9 @@ RootWindow::RootWindow()
       waiting_on_compositing_end_(false),
       draw_on_compositing_end_(false) {
   SetName("RootWindow");
-  gfx::Screen::SetInstance(screen_);
+
+  gfx::Screen::SetInstance(new ScreenAura(this));
+
   last_mouse_location_ = host_->QueryMouseLocation();
 
   ui::Compositor::Initialize(false);
@@ -148,12 +151,14 @@ gfx::Size RootWindow::GetHostSize() const {
   return rect.size();
 }
 
-void RootWindow::SetScreenWorkAreaInsets(const gfx::Insets& insets) {
-  if (screen_->work_area_insets() == insets)
+void RootWindow::SetMonitorWorkAreaInsets(const gfx::Insets& insets) {
+  Monitor* monitor = Env::GetInstance()->monitor_manager()->
+      GetMonitorNearestWindow(this);
+  if (monitor->work_area_insets() == insets)
     return;
-  screen_->set_work_area_insets(insets);
+  monitor->set_work_area_insets(insets);
   FOR_EACH_OBSERVER(RootWindowObserver, observers_,
-                    OnScreenWorkAreaInsetsChanged());
+                    OnMonitorWorkAreaInsetsChanged());
 }
 
 void RootWindow::SetCursor(gfx::NativeCursor cursor) {
@@ -788,6 +793,10 @@ void RootWindow::Init() {
   Show();
   compositor()->SetRootLayer(layer());
   host_->SetRootWindow(this);
+  // MonitorManager needs to access the root's bounds, so initialize after
+  // layer is created.
+  aura::Env::GetInstance()->SetMonitorManager(
+      aura::CreateSingleMonitorManager(this));
 }
 
 gfx::Rect RootWindow::GetInitialHostWindowBounds() const {