Improve panel related tests to make them more reliable

chrome/browser/ui/panels/panel_collection.h

Index: chrome/browser/ui/panels/panel_collection.h
diff --git a/chrome/browser/ui/panels/panel_collection.h b/chrome/browser/ui/panels/panel_collection.h
index 598ade7b943975334069ad640c98ec006e1196c4..9e1e5ef424ebef44d1876759f9205fcfe16dc818 100644
--- a/chrome/browser/ui/panels/panel_collection.h
+++ b/chrome/browser/ui/panels/panel_collection.h
@@ -34,15 +34,11 @@ class PanelCollection {
     TOP_POSITION = 0x2,
     // Do not update panel bounds. Only valid with DEFAULT_POSIITON.
     DO_NOT_UPDATE_BOUNDS = 0x4,
-    // Wait for a brief delay before refreshing layout of the collection after
-    // adding panel to the collection. If not set, the collection will refresh
-    // its layout immediately.
-    DELAY_LAYOUT_REFRESH = 0x8,
     // Do not refresh layout. Used by stacking.
-    NO_LAYOUT_REFRESH = 0x10,
+    NO_LAYOUT_REFRESH = 0x8,
     // Collapse other inactive stacked panels such the tha new panel can fit
     // within the working area. Used by stacking.
-    COLLAPSE_TO_FIT = 0x20
+    COLLAPSE_TO_FIT = 0x10
   };
 
   enum RemovalReason {