MonitorManager to manage multiple monitors.

chrome/test/base/browser_with_test_window_test.cc

Index: chrome/test/base/browser_with_test_window_test.cc
diff --git a/chrome/test/base/browser_with_test_window_test.cc b/chrome/test/base/browser_with_test_window_test.cc
index 25386443892e032800b31ec57c288f6b9527e591..f34079e18684b8e2263a7342bf6ad5669acba3d3 100644
--- a/chrome/test/base/browser_with_test_window_test.cc
+++ b/chrome/test/base/browser_with_test_window_test.cc
@@ -20,6 +20,8 @@
 #include "content/test/test_renderer_host.h"
 
 #if defined(USE_AURA)
+#include "ui/aura/env.h"
+#include "ui/aura/monitor_manager.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/test/test_activation_client.h"
 #include "ui/aura/test/test_screen.h"
@@ -51,6 +53,8 @@ void BrowserWithTestWindowTest::SetUp() {
   browser_->SetWindowForTesting(window_.get());
 #if defined(USE_AURA)
   root_window_.reset(new aura::RootWindow);
+  aura::Env::GetInstance()->SetMonitorManager(
+      aura::CreateSingleMonitorManager(root_window_.get()));
   gfx::Screen::SetInstance(new aura::TestScreen(root_window_.get()));
   test_activation_client_.reset(
       new aura::test::TestActivationClient(root_window_.get()));