Fix moving the mouse between two displays after the secondary display becomes primary.

ash/display/window_tree_host_manager.cc

Index: ash/display/window_tree_host_manager.cc
diff --git a/ash/display/window_tree_host_manager.cc b/ash/display/window_tree_host_manager.cc
index 6f2360776bcc7a057e4c106735ffa260175fc42c..f99f7a41b1c44ef3c24cdeefc658b9626ac3c977 100644
--- a/ash/display/window_tree_host_manager.cc
+++ b/ash/display/window_tree_host_manager.cc
@@ -457,13 +457,8 @@ void WindowTreeHostManager::SetPrimaryDisplay(
                                        new_primary_display.GetWorkAreaInsets());
 
   // Update the dispay manager with new display info.
-  std::vector<DisplayInfo> display_info_list;
-  display_info_list.push_back(
-      display_manager->GetDisplayInfo(primary_display_id));
-  display_info_list.push_back(
-      display_manager->GetDisplayInfo(ScreenUtil::GetSecondaryDisplay().id()));
   GetDisplayManager()->set_force_bounds_changed(true);
-  GetDisplayManager()->UpdateDisplays(display_info_list);

[stevenjb, 2016/01/25 21:42:55]

Can we now rename DisplayManager::UpdateDisplays(vector) to
DisplayManager::UpdateDisplaysImpl(vector) so we don't have the unfortunate
situation where DisplayManager has two methods with the same name (we strongly
discourage that in Chrome)? This appears to have been the only place outside of
DisplayManager where the (vector) version is called.

[jdufault, 2016/01/25 22:48:46]

There are some tests that use the method. Given that, what do you think of
renaming UpdateDisplays(vector) to UpdateDisplaysTo(vector)?

+  GetDisplayManager()->UpdateDisplays();
   GetDisplayManager()->set_force_bounds_changed(false);
 }