[Material][Mac] Fix tabstrip and avatar button hierarchy

chrome/browser/ui/cocoa/browser_window_controller.mm

Index: chrome/browser/ui/cocoa/browser_window_controller.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.mm b/chrome/browser/ui/cocoa/browser_window_controller.mm
index 4ab8af89a5846f6f22131b898c78520a55fe9f89..0c3781441f3f9da1beb9b9c78b45f6c2ebc2cffc 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller.mm
@@ -1904,6 +1904,10 @@ willAnimateFromState:(BookmarkBar::State)oldState
   return [presentationModeController_ menubarOffset];
 }
 
+- (NSView*)avatarView {
+  return [avatarButtonController_ view];
+}
+
 - (void)enterWebContentFullscreen {
   // HTML5 Fullscreen should only use AppKit fullscreen in 10.10+.
   // However, if the user is using multiple monitors and turned off