Promotes more accessors from WmShell to Shell

ash/common/wallpaper/wallpaper_view.cc

Index: ash/common/wallpaper/wallpaper_view.cc
diff --git a/ash/common/wallpaper/wallpaper_view.cc b/ash/common/wallpaper/wallpaper_view.cc
index 843f95ac7f86c5c4bcd1f37a5487c08a16058f10..8fedb4ad020644c305e0fef167369c8fa4d9ebd1 100644
--- a/ash/common/wallpaper/wallpaper_view.cc
+++ b/ash/common/wallpaper/wallpaper_view.cc
@@ -85,7 +85,7 @@ class PreEventDispatchHandler : public ui::EventHandler {
   void OnMouseEvent(ui::MouseEvent* event) override {
     CHECK_EQ(ui::EP_PRETARGET, event->phase());
     WindowSelectorController* controller =
-        WmShell::Get()->window_selector_controller();
+        Shell::Get()->window_selector_controller();
     if (event->type() == ui::ET_MOUSE_RELEASED && controller->IsSelecting()) {
       controller->ToggleOverview();
       event->StopPropagation();
@@ -95,7 +95,7 @@ class PreEventDispatchHandler : public ui::EventHandler {
   void OnGestureEvent(ui::GestureEvent* event) override {
     CHECK_EQ(ui::EP_PRETARGET, event->phase());
     WindowSelectorController* controller =
-        WmShell::Get()->window_selector_controller();
+        Shell::Get()->window_selector_controller();
     if (event->type() == ui::ET_GESTURE_TAP && controller->IsSelecting()) {
       controller->ToggleOverview();
       event->StopPropagation();