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

chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #import "base/mac/mac_util.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 597 matching lines @@
 
 void LocationBarViewMac::OnAddedToWindow() {
   UpdateColorsToMatchTheme();
 }
 
 void LocationBarViewMac::OnThemeChanged() {
   UpdateColorsToMatchTheme();
 }
 
 void LocationBarViewMac::OnChanged() {
-  NSImage* image = nil;
-  if (ui::MaterialDesignController::IsModeMaterial()) {
-    UpdateLocationIcon();
-  } else {
+  if (!ui::MaterialDesignController::IsModeMaterial()) {
     const int resource_id = omnibox_view_->GetIcon();
-    image = OmniboxViewMac::ImageForResource(resource_id);
+    NSImage* image = OmniboxViewMac::ImageForResource(resource_id);
     location_icon_decoration_->SetImage(image);
     ev_bubble_decoration_->SetImage(image);
     Layout();
+    return;
   }
+  UpdateLocationIcon();
 }
 
 void LocationBarViewMac::OnSetFocus() {
   // Update the keyword and search hint states.
   OnChanged();
 }
 
 void LocationBarViewMac::ShowURL() {
   omnibox_view_->ShowURL();
 }
@@ skipping 168 matching lines @@
   return zoom_decoration_->UpdateIfNecessary(
       ui_zoom::ZoomController::FromWebContents(web_contents),
       default_zoom_changed,
       in_dark_mode);
 }
 
 void LocationBarViewMac::OnDefaultZoomLevelChanged() {
   if (UpdateZoomDecoration(/*default_zoom_changed=*/true))
     OnDecorationsChanged();
 }