Policy: check MustRemainInstalled in addition to UserMayModifySettings before offering uninstall

Review URL: https://codereview.chromium.org/903453002

Cr-Commit-Position: refs/heads/master@{#314784}

chrome/browser/extensions/extension_context_menu_model.cc

@@ -156,8 +156,10 @@ bool ExtensionContextMenuModel::IsCommandIdEnabled(int command_id) const {
         extension_action_->HasPopup(SessionTabHelper::IdForTab(web_contents));
   } else if (command_id == UNINSTALL) {
     // Some extension types can not be uninstalled.
-    return extensions::ExtensionSystem::Get(
-        profile_)->management_policy()->UserMayModifySettings(extension, NULL);
+    extensions::ManagementPolicy* policy =
+        extensions::ExtensionSystem::Get(profile_)->management_policy();
+    return policy->UserMayModifySettings(extension, nullptr) &&
+           !policy->MustRemainInstalled(extension, nullptr);
   }
   return true;
 }

chrome/browser/ui/views/apps/app_info_dialog/app_info_footer_panel.cc

@@ -184,7 +184,8 @@ void AppInfoFooterPanel::UninstallApp() {
 }
 
 bool AppInfoFooterPanel::CanUninstallApp() const {
-  return extensions::ExtensionSystem::Get(profile_)
-      ->management_policy()
-      ->UserMayModifySettings(app_, NULL);
+  extensions::ManagementPolicy* policy =
+      extensions::ExtensionSystem::Get(profile_)->management_policy();
+  return policy->UserMayModifySettings(app_, nullptr) &&
+         !policy->MustRemainInstalled(app_, nullptr);
 }

extensions/browser/api/management/management_api.cc

@@ -514,9 +514,10 @@ bool ManagementUninstallFunctionBase::Uninstall(
     return false;
   }
 
-  if (!ExtensionSystem::Get(browser_context())
-           ->management_policy()
-           ->UserMayModifySettings(target_extension, NULL)) {
+  ManagementPolicy* policy =
+      ExtensionSystem::Get(browser_context())->management_policy();
+  if (!policy->UserMayModifySettings(target_extension, nullptr) ||
+      policy->MustRemainInstalled(target_extension, nullptr)) {
     error_ = ErrorUtils::FormatErrorMessage(keys::kUserCantModifyError,
                                             extension_id_);
     return false;