Show Previews UI at commit for Client LoFi with network-serivce

Client LoFi infobar will be shown when lofi response is received, and android
omnibox UI will be shown at navigation commit. This CL changes the behavior to
show the infobar UI as well at navigation commit, when NetworkService is
enabled, since the response headers of subresources would not be
received in the browser process.

Bug: 893728
Change-Id: I66122590e80974449528635892b1c720efe04450
Reviewed-on: https://chromium-review.googlesource.com/c/1327556
Commit-Queue: rajendrant <rajendrant@chromium.org>
Reviewed-by: Scott Little <sclittle@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607102}

chrome/browser/previews/previews_ui_tab_helper.cc

@@ -35,6 +35,7 @@
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "net/http/http_response_headers.h"
+#include "services/network/public/cpp/features.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "url/gurl.h"
 
@@ -84,10 +85,12 @@ bool ShouldShowUIForPreviewsType(previews::PreviewsType type) {
   if (type == previews::PreviewsType::NONE)
     return false;
 
-  // Show the UI for LoFi at commit if the UI is the Android Omnibox.
-  if (type == previews::PreviewsType::LOFI)
-    return previews::params::IsPreviewsOmniboxUiEnabled();
-
+  // Show the UI for LoFi at commit if the UI is the Android Omnibox or when
+  // network-service is enabled.
+  if (type == previews::PreviewsType::LOFI) {
+    return previews::params::IsPreviewsOmniboxUiEnabled() ||
+           base::FeatureList::IsEnabled(network::features::kNetworkService);
+  }
   return true;
 }