PS - Showing permission prompt for activeTab

chrome/browser/chromeos/extensions/active_tab_permission_granter_delegate_chromeos.cc

+// Copyright 2017 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/chromeos/extensions/active_tab_permission_granter_delegate_chromeos.h"
+
+#include <map>
+
+#include "base/lazy_instance.h"
+#include "chrome/browser/chromeos/extensions/device_local_account_management_policy_provider.h"
+#include "chrome/browser/chromeos/extensions/public_session_permission_helper.h"
+#include "chrome/browser/profiles/profiles_state.h"
+#include "extensions/common/extension.h"
+#include "extensions/common/permissions/api_permission.h"
+#include "extensions/common/permissions/api_permission_set.h"
+
+namespace extensions {
+
+namespace {
+
+base::LazyInstance<std::map<ExtensionId, bool>>::Leaky
+    g_active_tab_granted_map = LAZY_INSTANCE_INITIALIZER;
+
+void UpdateActiveTabGranted(const Extension* extension,
+                            const PermissionIDSet& allowed_permissions) {
+  g_active_tab_granted_map.Get()[extension->id()] =
+      allowed_permissions.ContainsID(APIPermission::kActiveTab);
+}
+
+}  // namespace
+
+ActiveTabPermissionGranterDelegateChromeOS::
+    ActiveTabPermissionGranterDelegateChromeOS() {}
+
+ActiveTabPermissionGranterDelegateChromeOS::
+    ~ActiveTabPermissionGranterDelegateChromeOS() {}
+
+bool ActiveTabPermissionGranterDelegateChromeOS::ActiveTabPermissionGranted(
+    const Extension* extension,
+    content::WebContents* web_contents) {
+  bool active_tab_granted = g_active_tab_granted_map.Get()[extension->id()];
+
+  if (!profiles::IsPublicSession() || active_tab_granted ||
+      chromeos::DeviceLocalAccountManagementPolicyProvider::IsWhitelisted(
+          extension->id())) {
+    return true;
+  }
+
+  permission_helper::HandlePermissionRequest(

[Ivan Šandrk, 2017/05/05 16:24:26]

Should I add a brief comment here explaining the mechanics?

+      *extension, {APIPermission::kActiveTab}, web_contents,
+      base::Bind(&UpdateActiveTabGranted, extension),
+      permission_helper::PromptFactory());
+
+  return false;
+}
+
+}  // namespace extensions