[Mac][Material Design] Update Omnibox dropdown on Mac to MD

chrome/browser/ui/cocoa/omnibox/omnibox_popup_separator_view.h

Index: chrome/browser/ui/cocoa/omnibox/omnibox_popup_separator_view.h
diff --git a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_separator_view.h b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_separator_view.h
index ae2355a742b26481296797cf03710727fb89bcf7..1b91be76701143f4d3fa1e332c70131e0bc4d41c 100644
--- a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_separator_view.h
+++ b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_separator_view.h
@@ -19,9 +19,12 @@
 
 // A view used to draw a drop shadow beneath the omnibox popup.
 @interface OmniboxPopupBottomSeparatorView : NSView {
+ @private
+  BOOL isDarkTheme_;
 }
 
 + (CGFloat)preferredHeight;
+- (instancetype)initWithFrame:(NSRect)frame forDarkTheme:(BOOL)isDarkTheme;
 
 @end