Turn off the tip for the sytem tray menu and the app list (ChromeOS).

ash/system/tray/system_tray.cc

Index: ash/system/tray/system_tray.cc
diff --git a/ash/system/tray/system_tray.cc b/ash/system/tray/system_tray.cc
index 677c710c38df64fdce32c1f770f4b9318d6de41c..eb183ec0c122191c2b2bea48b4b451bbc8aa0c06 100644
--- a/ash/system/tray/system_tray.cc
+++ b/ash/system/tray/system_tray.cc
@@ -89,6 +89,11 @@ class SystemBubbleWrapper {
     bubble_->InitView(anchor, login_status, init_params);
     bubble_wrapper_.reset(
         new internal::TrayBubbleWrapper(tray, bubble_->bubble_view()));
+    if (ash::switches::UseAlternateShelfLayout()) {
+      // The system bubble should not have an arrow.
+      bubble_->bubble_view()->SetArrowPaintType(
+          views::BubbleBorder::PAINT_NONE);
+    }

[simonhong_, 2013/06/15 15:21:07]

This code is actually changing PAINT_NORMAL to PAINT_NONE after
creating(showing) the bubble. (tray bubble is created at the ctor of
TrayBubbleWrapper).
I think setting the arrow before the bubble_view_->InitializeAndShowBubble() is
better than here.

   }
 
   // Convenience accessors:
@@ -510,7 +515,8 @@ void SystemTray::AnchorUpdated() {
   }
   if (system_bubble_) {
     system_bubble_->bubble_view()->UpdateBubble();
-    UpdateBubbleViewArrow(system_bubble_->bubble_view());
+    if (!ash::switches::UseAlternateShelfLayout())
+      UpdateBubbleViewArrow(system_bubble_->bubble_view());
   }
 }