Print Preview Componentization: Add to upcoming UI features flag

Add new print preview to the upcoming UI features flag.

Bug: 773928
Change-Id: Ia1fe0883fba0a76b6bbf75b86b932f3b1abf0947
Reviewed-on: https://chromium-review.googlesource.com/1103292Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568105}

chrome/browser/flag_descriptions.cc

@@ -555,7 +555,8 @@ const char kEnableNetworkServiceInProcessDescription[] =
 
 const char kEnableNewPrintPreview[] = "Enable new Print Preview UI";
 const char kEnableNewPrintPreviewDescription[] =
-    "If enabled, Print Preview will display a newer UI";
+    "If enabled, Print Preview will display a newer UI. This feature is "
+    "activated if either this flag or #upcoming-ui-features is enabled.";
 
 const char kEnableNightLightName[] = "Enable Night Light";
 const char kEnableNightLightDescription[] =

chrome/browser/ui/webui/print_preview/print_preview_ui.cc

@@ -51,6 +51,7 @@
 #include "printing/page_size_margins.h"
 #include "printing/print_job_constants.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/base/ui_base_features.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/web_dialogs/web_dialog_delegate.h"
 #include "ui/web_dialogs/web_dialog_ui.h"
@@ -578,7 +579,8 @@ PrintPreviewUI::PrintPreviewUI(content::WebUI* web_ui)
   Profile* profile = Profile::FromWebUI(web_ui);
 
   bool new_print_preview_enabled =
-      base::FeatureList::IsEnabled(features::kNewPrintPreview);
+      base::FeatureList::IsEnabled(features::kNewPrintPreview) ||
+      base::FeatureList::IsEnabled(features::kExperimentalUi);
   if (new_print_preview_enabled) {
     content::WebUIDataSource::Add(profile,
                                   CreateNewPrintPreviewUISource(profile));