Add a top shadow to material design omnibox dropdown

chrome/browser/ui/views/location_bar/location_bar_view.h

Index: chrome/browser/ui/views/location_bar/location_bar_view.h
diff --git a/chrome/browser/ui/views/location_bar/location_bar_view.h b/chrome/browser/ui/views/location_bar/location_bar_view.h
index efbcbd16578d44396b1cec79520890243987fb03..cfadf7470ae49e40ecd00ea474c87ebd6d452060 100644
--- a/chrome/browser/ui/views/location_bar/location_bar_view.h
+++ b/chrome/browser/ui/views/location_bar/location_bar_view.h
@@ -223,11 +223,14 @@ class LocationBarView : public LocationBar,
 
   // Returns the position and width that the popup should be, and also the left
   // edge that the results should align themselves to (which will leave some
-  // border on the left of the popup).
+  // border on the left of the popup). |top_edge_overlap| specifies the number
+  // of pixels the top edge of the popup should overlap the bottom edge of
+  // the toolbar.
   void GetOmniboxPopupPositioningInfo(gfx::Point* top_left_screen_coord,
                                       int* popup_width,
                                       int* left_margin,
-                                      int* right_margin);
+                                      int* right_margin,
+                                      int top_edge_overlap);
 
   // Updates the controller, and, if |contents| is non-null, restores saved
   // state that the tab holds.