Some more fixes to cros system tray icons (esp. screen tray items)

ash/common/system/tray/tray_item_view.cc

Index: ash/common/system/tray/tray_item_view.cc
diff --git a/ash/common/system/tray/tray_item_view.cc b/ash/common/system/tray/tray_item_view.cc
index 3cc2830a9aad21f8e727bb61c36d28351ae938dd..38c4d749349e85e32f69cc59335627f719d23a26 100644
--- a/ash/common/system/tray/tray_item_view.cc
+++ b/ash/common/system/tray/tray_item_view.cc
@@ -83,9 +83,10 @@ int TrayItemView::GetAnimationDurationMS() {
 
 gfx::Size TrayItemView::GetPreferredSize() const {
   gfx::Size size;
+  DCHECK_EQ(1, child_count());

[tdanderson, 2016/11/01 20:25:08]

Can you please add documentation somewhere in tray_item_view.h clarifying that
exactly one of |label_| and |image_view_| is non-null?

[Evan Stade, 2016/11/01 23:45:17]

Done.

   if (MaterialDesignController::UseMaterialDesignSystemIcons()) {
     gfx::Size inner_size = views::View::GetPreferredSize();
-    if (image_view_ && child_count() == 1)
+    if (image_view_)
       inner_size = gfx::Size(kTrayIconSize, kTrayIconSize);
     gfx::Rect rect(inner_size);
     rect.Inset(gfx::Insets(-GetTrayConstant(TRAY_IMAGE_ITEM_PADDING)));