Make ui::test::EventGenerator work with PointerEvents in mash

ash/common/system/tray/system_tray_unittest.cc

Index: ash/common/system/tray/system_tray_unittest.cc
diff --git a/ash/common/system/tray/system_tray_unittest.cc b/ash/common/system/tray/system_tray_unittest.cc
index 90b6832400ca29ffa5373b05eeb60c39e45d38f0..ee7977b173cea225567ee6e9a25c9e109a61fdac 100644
--- a/ash/common/system/tray/system_tray_unittest.cc
+++ b/ash/common/system/tray/system_tray_unittest.cc
@@ -427,10 +427,6 @@ TEST_F(SystemTrayTest, TrayBoundsInWidget) {
 }
 
 TEST_F(SystemTrayTest, PersistentBubble) {
-  // TODO: investigate why this fails in mash. http://crbug.com/695559.
-  if (WmShell::Get()->IsRunningInMash())
-    return;
-
   SystemTray* tray = GetPrimarySystemTray();
   ASSERT_TRUE(tray->GetWidget());
 
@@ -448,6 +444,7 @@ TEST_F(SystemTrayTest, PersistentBubble) {
   base::RunLoop().RunUntilIdle();
   ASSERT_FALSE(tray->HasSystemBubble());
 
+  // Clicking outside the bubble should close it.
   tray->ShowDefaultView(BUBBLE_CREATE_NEW);
   ASSERT_TRUE(tray->HasSystemBubble());
   {