Change EventGenerator to take a RootWindow at construction instead of just assuming one via RootWin…

ash/wm/window_modality_controller_unittest.cc

Index: ash/wm/window_modality_controller_unittest.cc
===================================================================
--- ash/wm/window_modality_controller_unittest.cc	(revision 122697)
+++ ash/wm/window_modality_controller_unittest.cc	(working copy)
@@ -4,6 +4,7 @@
 
 #include "ash/wm/window_modality_controller.h"
 
+#include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/client/aura_constants.h"
@@ -184,7 +185,8 @@
 
   {
     // Clicking a point within w1 should activate that window.
-    aura::test::EventGenerator generator(gfx::Point(10, 10));
+    aura::test::EventGenerator generator(Shell::GetRootWindow(),
+                                         gfx::Point(10, 10));
     generator.ClickLeftButton();
     EXPECT_TRUE(IsActiveWindow(w1.get()));
   }
@@ -193,7 +195,8 @@
 
   {
     // Clicking a point within w1 should activate w11.
-    aura::test::EventGenerator generator(gfx::Point(10, 10));
+    aura::test::EventGenerator generator(Shell::GetRootWindow(),
+                                         gfx::Point(10, 10));
     generator.ClickLeftButton();
     EXPECT_TRUE(IsActiveWindow(w11.get()));
   }