ash: A number of ui/ux changes from feedback/to better match the mocks.

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 39d176bcb747e733a66e5e1709c635c0edd06305..879a00ba12690c2de941c021a1f283269fd67b8c 100644
--- a/ash/system/tray/system_tray.cc
+++ b/ash/system/tray/system_tray.cc
@@ -7,6 +7,7 @@
 #include "ash/shell.h"
 #include "ash/shell/panel_window.h"
 #include "ash/shell_window_ids.h"
+#include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/system_tray_item.h"
 #include "ash/system/user/login_status.h"
@@ -298,7 +299,7 @@ SystemTray::SystemTray()
       popup_(NULL) {
   container_ = new views::View;
   container_->SetLayoutManager(new views::BoxLayout(
-      views::BoxLayout::kHorizontal, 5, 0, 3));
+      views::BoxLayout::kHorizontal, 5, 0, kTrayPaddingBetweenItems));
   container_->set_background(new SystemTrayBackground);
   set_border(views::Border::CreateEmptyBorder(0, 0,
         kPaddingFromBottomOfScreen, kPaddingFromRightEdgeOfScreen));