Allow enhanced bookmarks external component extensions to be disabled

chrome/browser/extensions/external_component_loader.cc

 // Copyright (c) 2013 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_component_loader.h"
 
+#include "base/sha1.h"
+#include "base/strings/string_number_conversions.h"
 #include "chrome/browser/bookmarks/enhanced_bookmarks_features.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/search/hotword_service_factory.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "components/signin/core/browser/signin_manager.h"
 
 namespace {
 
 bool IsUserSignedin(Profile* profile) {
   SigninManagerBase* signin = SigninManagerFactory::GetForProfile(profile);
   return signin && !signin->GetAuthenticatedUsername().empty();
 }
 
 }  // namespace
 
 namespace extensions {
 
 ExternalComponentLoader::ExternalComponentLoader(Profile* profile)
     : profile_(profile) {
 }
 
 ExternalComponentLoader::~ExternalComponentLoader() {}
 
+// static
+bool ExternalComponentLoader::IsModifiable(
+    const extensions::Extension* extension) {
+  if (extension->location() == extensions::Manifest::EXTERNAL_COMPONENT) {
+    static const char* enhanced_extension_hashes[] = {
+        "D5736E4B5CF695CB93A2FB57E4FDC6E5AFAB6FE2",  // http://crbug.com/312900
+        "D57DE394F36DC1C3220E7604C575D29C51A6C495",  // http://crbug.com/319444
+        "3F65507A3B39259B38C8173C6FFA3D12DF64CCE9"   // http://crbug.com/371562
+    };
+    std::string hash = base::SHA1HashString(extension->id());
+    hash = base::HexEncode(hash.c_str(), hash.length());
+    for (size_t i = 0; i < arraysize(enhanced_extension_hashes); i++)
+      if (hash == enhanced_extension_hashes[i])
+        return true;
+  }
+  return false;
+}
+
 void ExternalComponentLoader::StartLoading() {
   prefs_.reset(new base::DictionaryValue());
   std::string appId = extension_misc::kInAppPaymentsSupportAppId;
   prefs_->SetString(appId + ".external_update_url",
                     extension_urls::GetWebstoreUpdateUrl().spec());
 
   if (HotwordServiceFactory::IsHotwordAllowed(profile_)) {
     std::string hotwordId = extension_misc::kHotwordExtensionId;
     prefs_->SetString(hotwordId + ".external_update_url",
                       extension_urls::GetWebstoreUpdateUrl().spec());
   }
 
   UpdateBookmarksExperimentState(
       profile_->GetPrefs(),
       g_browser_process->local_state(),
       IsUserSignedin(profile_),
       BOOKMARKS_EXPERIMENT_ENABLED_FROM_SYNC_UNKNOWN);
   std::string ext_id;
   if (GetBookmarksExperimentExtensionID(profile_->GetPrefs(), &ext_id) &&
       !ext_id.empty()) {
     prefs_->SetString(ext_id + ".external_update_url",
                       extension_urls::GetWebstoreUpdateUrl().spec());
   }
 
   LoadFinished();
 }
 
 }  // namespace extensions