Add recommended extension installation support

chrome/browser/extensions/external_policy_loader.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/external_policy_loader.h"
 
+#include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/external_provider_impl.h"
 
 namespace extensions {
 
-ExternalPolicyLoader::ExternalPolicyLoader(ExtensionManagement *settings)
-    : settings_(settings) {
+ExternalPolicyLoader::ExternalPolicyLoader(ExtensionManagement* settings,
+                                           InstallationType type)
+    : settings_(settings), type_(type) {
   settings_->AddObserver(this);
 }
 
 ExternalPolicyLoader::~ExternalPolicyLoader() {
   settings_->RemoveObserver(this);
 }
 
 void ExternalPolicyLoader::OnExtensionManagementSettingsChanged() {
   StartLoading();
 }
 
 // static
 void ExternalPolicyLoader::AddExtension(base::DictionaryValue* dict,
                                         const std::string& extension_id,
                                         const std::string& update_url) {
   dict->SetString(base::StringPrintf("%s.%s", extension_id.c_str(),
                                      ExternalProviderImpl::kExternalUpdateUrl),
                   update_url);
 }
 
 void ExternalPolicyLoader::StartLoading() {
-  prefs_ = settings_->GetForceInstallList();
+  switch (type_) {
+    case FORCED:
+      prefs_ = settings_->GetForceInstallList();
+      break;
+    case RECOMMENDED:
+      prefs_ = settings_->GetRecommendedInstallList();
+      break;
+    default:
+      NOTREACHED();

[Finnur, 2014/10/06 19:35:27]

Leaving out the default case altogether is better than adding a default with a
NOTREACHED, because then the mistake (forgetting to add to this switch
statement) is caught at compile time, and not at runtime...

[binjin, 2014/10/07 09:29:23]

Done.

+  }
   LoadFinished();
 }
 
 }  // namespace extensions