Add a do_not_sync pref to ExtensionPrefs.

chrome/browser/extensions/extension_sync_bundle.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/extension_sync_bundle.h"
 
 #include "base/location.h"
 #include "chrome/browser/extensions/extension_sync_service.h"
+#include "chrome/browser/extensions/extension_util.h"
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/sync_helper.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_set.h"
 #include "sync/api/sync_change_processor.h"
 #include "sync/api/sync_error_factory.h"
 
 namespace extensions {
 
 ExtensionSyncBundle::ExtensionSyncBundle(
     ExtensionSyncService* extension_sync_service)
@@ skipping 116 matching lines @@
        ++i) {
     pending_extensions.push_back(i->second);
   }
 
   return pending_extensions;
 }
 
 void ExtensionSyncBundle::GetExtensionSyncDataListHelper(
     const ExtensionSet& extensions,
     std::vector<ExtensionSyncData>* sync_data_list) const {
+  Profile* profile = extension_sync_service_->profile();
+
   for (ExtensionSet::const_iterator it = extensions.begin();
        it != extensions.end(); ++it) {
     const Extension& extension = *it->get();
     // If we have pending extension data for this extension, then this
     // version is out of date.  We'll sync back the version we got from
     // sync.
-    if (IsSyncing() && sync_helper::IsSyncableExtension(&extension) &&
+    if (IsSyncing() && util::ShouldSyncExtension(&extension, profile) &&

[not at google - send to devlin, 2014/06/13 20:01:22]

could you add a comment to sync_helper.h saying "you probably want to use
util::ShoudSyncExtension not these methods".

[xiyuan, 2014/06/13 20:35:42]

Done.

         !HasPendingExtensionId(extension.id())) {
       sync_data_list->push_back(
           extension_sync_service_->GetExtensionSyncData(extension));
     }
   }
 }
 
 void ExtensionSyncBundle::AddExtension(const std::string& id) {
   synced_extensions_.insert(id);
 }
 
 void ExtensionSyncBundle::RemoveExtension(const std::string& id) {
   synced_extensions_.erase(id);
 }
 
 void ExtensionSyncBundle::MarkPendingExtensionSynced(const std::string& id) {
   pending_sync_data_.erase(id);
   synced_extensions_.insert(id);
 }
 
 }  // namespace extensions