Rename Launcher to Shelf.

ash/system/tray/system_tray_bubble.cc

Index: ash/system/tray/system_tray_bubble.cc
diff --git a/ash/system/tray/system_tray_bubble.cc b/ash/system/tray/system_tray_bubble.cc
index 1aa60bc5541dd16d2b4e23341f7154d8c402cf97..b3a0451493b65003a1ebf94393b33ecc126b3387 100644
--- a/ash/system/tray/system_tray_bubble.cc
+++ b/ash/system/tray/system_tray_bubble.cc
@@ -340,11 +340,11 @@ bool SystemTrayBubble::IsVisible() {
   return bubble_view() && bubble_view()->GetWidget()->IsVisible();
 }
 
-bool SystemTrayBubble::ShouldShowLauncher() const {
+bool SystemTrayBubble::ShouldShowShelf() const {
   for (std::vector<ash::SystemTrayItem*>::const_iterator it = items_.begin();
        it != items_.end();
        ++it) {
-    if ((*it)->ShouldShowLauncher())
+    if ((*it)->ShouldShowShelf())
       return true;
   }
   return false;