cleanup: pass string as const reference from c/b/extension/api

chrome/browser/extensions/api/developer_private/developer_private_api.cc

 // Copyright (c) 2012 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/extensions/api/developer_private/developer_private_api.h"
 
 #include "apps/app_load_service.h"
 #include "apps/app_restore_service.h"
 #include "apps/app_window.h"
 #include "apps/app_window_registry.h"
@@ skipping 77 matching lines @@
 
 namespace {
 
 const base::FilePath::CharType kUnpackedAppsFolder[]
     = FILE_PATH_LITERAL("apps_target");
 
 ExtensionUpdater* GetExtensionUpdater(Profile* profile) {
     return profile->GetExtensionService()->updater();
 }
 
-GURL GetImageURLFromData(std::string contents) {
+GURL GetImageURLFromData(const std::string& contents) {
   std::string contents_base64;
   base::Base64Encode(contents, &contents_base64);
 
   // TODO(dvh): make use of content::kDataScheme. Filed as crbug/297301.
   const char kDataURLPrefix[] = "data:image;base64,";
   return GURL(kDataURLPrefix + contents_base64);
 }
 
 GURL GetDefaultImageURL(developer_private::ItemType type) {
   int icon_resource_id;
@@ skipping 718 matching lines @@
       ExtensionActionAPI::SetBrowserActionVisibility(
           prefs, extension->id(), true);
     }
   } else {
     service->DisableExtension(extension_id, Extension::DISABLE_USER_ACTION);
   }
   return true;
 }
 
 void DeveloperPrivateEnableFunction::OnRequirementsChecked(
-    std::string extension_id,
+    const std::string& extension_id,
     std::vector<std::string> requirements_errors) {
   if (requirements_errors.empty()) {
     ExtensionService* service = GetProfile()->GetExtensionService();
     service->EnableExtension(extension_id);
   } else {
     ExtensionErrorReporter::GetInstance()->ReportError(
         base::UTF8ToUTF16(JoinString(requirements_errors, ' ')),
         true);  // Be noisy.
   }
   Release();
@@ skipping 504 matching lines @@
   }
 
   error_ui_util::HandleOpenDevTools(dict);
 
   return true;
 }
 
 }  // namespace api
 
 }  // namespace extensions