lacros: Prevent experimental banner from showing up more than once.

This CL stores whether the banner has already been shown as a local
pref. If it has been shown, then it is not shown again.

Bug: 1144321
Change-Id: I5dd97d6e4263c308bd14d90a480cf6cdeb7e7611
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2593282Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837382}

chrome/browser/BUILD.gn

@@ -4601,6 +4601,8 @@ static_library("browser") {
       "lacros/immersive_context_lacros.h",
       "lacros/lacros_chrome_service_delegate_impl.cc",
       "lacros/lacros_chrome_service_delegate_impl.h",
+      "lacros/lacros_prefs.cc",
+      "lacros/lacros_prefs.h",
       "lacros/metrics_reporting_observer.cc",
       "lacros/metrics_reporting_observer.h",
       "lacros/snap_controller_lacros.cc",

chrome/browser/lacros/lacros_prefs.cc

+// Copyright 2020 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.
+
+#include "chrome/browser/lacros/lacros_prefs.h"
+
+#include "components/prefs/pref_registry_simple.h"
+
+namespace lacros_prefs {
+
+const char kShowedExperimentalBannerPref[] =
+    "lacros.showed_experimental_banner";
+
+void RegisterLocalStatePrefs(PrefRegistrySimple* registry) {
+  registry->RegisterBooleanPref(kShowedExperimentalBannerPref,
+                                /*default_value=*/false);
+}
+
+}  // namespace lacros_prefs

chrome/browser/lacros/lacros_prefs.h

+// Copyright 2020 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.
+
+#ifndef CHROME_BROWSER_LACROS_LACROS_PREFS_H_
+#define CHROME_BROWSER_LACROS_LACROS_PREFS_H_
+
+class PrefRegistrySimple;
+
+namespace lacros_prefs {
+
+// A preference for whether the "this is an experimental feature" banner has
+// been shown to the user.
+extern const char kShowedExperimentalBannerPref[];
+
+// Local state prefs are also known as browser-wide prefs. This function
+// registers Lacros-related local state prefs.
+void RegisterLocalStatePrefs(PrefRegistrySimple* registry);
+
+}  // namespace lacros_prefs
+
+#endif  // CHROME_BROWSER_LACROS_LACROS_PREFS_H_

chrome/browser/prefs/browser_prefs.cc

@@ -389,6 +389,10 @@
 #include "chrome/browser/browser_switcher/browser_switcher_prefs.h"
 #endif
 
+#if BUILDFLAG(IS_CHROMEOS_LACROS)
+#include "chrome/browser/lacros/lacros_prefs.h"
+#endif
+
 #if !defined(OS_ANDROID) && !BUILDFLAG(IS_CHROMEOS_ASH)
 #include "chrome/browser/device_identity//device_oauth2_token_store_desktop.h"
 #include "chrome/browser/downgrade/downgrade_prefs.h"
@@ -786,6 +790,10 @@ void RegisterLocalState(PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(kKeyCreated, false);
 #endif
 
+#if BUILDFLAG(IS_CHROMEOS_LACROS)
+  lacros_prefs::RegisterLocalStatePrefs(registry);
+#endif
+
 #if defined(OS_WIN)
   OSCrypt::RegisterLocalPrefs(registry);
   registry->RegisterBooleanPref(prefs::kRendererCodeIntegrityEnabled, true);

chrome/browser/ui/startup/startup_browser_creator_impl.cc

@@ -79,6 +79,7 @@
 #endif
 
 #if BUILDFLAG(IS_CHROMEOS_LACROS)
+#include "chrome/browser/lacros/lacros_prefs.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/infobars/core/simple_alert_infobar_delegate.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -574,15 +575,25 @@ void StartupBrowserCreatorImpl::AddInfoBarsIfNecessary(
         InfoBarService::FromWebContents(web_contents);
 
 #if BUILDFLAG(IS_CHROMEOS_LACROS)
-    // Show the experimental lacros info bar. auto_expire must be set to false,
-    // since otherwise an automated navigation [which can happen at launch] will
-    // cause the info bar to disappear.
-    SimpleAlertInfoBarDelegate::Create(
-        infobar_service,
-        infobars::InfoBarDelegate::EXPERIMENTAL_INFOBAR_DELEGATE_LACROS,
-        /*vector_icon=*/nullptr,
-        l10n_util::GetStringUTF16(IDS_EXPERIMENTAL_LACROS_WARNING_MESSAGE),
-        /*auto_expire=*/false, /*should_animate=*/false);
+    PrefService* local_state = g_browser_process->local_state();
+    if (local_state) {
+      if (!local_state->GetBoolean(
+              lacros_prefs::kShowedExperimentalBannerPref)) {
+        // Show the experimental lacros info bar. auto_expire must be set to
+        // false, since otherwise an automated navigation [which can happen at
+        // launch] will cause the info bar to disappear.
+        SimpleAlertInfoBarDelegate::Create(
+            infobar_service,
+            infobars::InfoBarDelegate::EXPERIMENTAL_INFOBAR_DELEGATE_LACROS,
+            /*vector_icon=*/nullptr,
+            l10n_util::GetStringUTF16(IDS_EXPERIMENTAL_LACROS_WARNING_MESSAGE),
+            /*auto_expire=*/false, /*should_animate=*/false);
+
+        // Mark the pref as shown, so that we don't show the banner again.
+        local_state->SetBoolean(lacros_prefs::kShowedExperimentalBannerPref,
+                                true);
+      }
+    }
 #endif
 
     if (!google_apis::HasAPIKeyConfigured())