Resubmit: Add a Restore() method to ValueStore and make StorageAPI use it

Resubmit of: https://codereview.chromium.org/165223003/

TBR=mpcomplete@chromium.org
TBR=joaodasilva@chromium.org

---------------------------------
Add a Restore() method to ValueStore and make StorageAPI use it
Take the first steps in preventing the Storage from getting and staying
corrupted. This lets us Restore() a ValueStore when it's corrputed, and tries to
do so in the StorageAPI calls.
This also refactors so that there's a Local and Sync SettingsBackend - this has
the added advantage of meaning we don't decorate the Local stores with Sync
behavior.
BUG=261623

Review URL: https://codereview.chromium.org/176963006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253353 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 2 deletions

diff --git a/chrome/browser/extensions/test_extension_system.cc b/chrome/browser/extensions/test_extension_system.cc
index 416ca66..67e522a 100644
--- a/chrome/browser/extensions/test_extension_system.cc
+++ b/chrome/browser/extensions/test_extension_system.cc
@@ -152,10 +152,12 @@ TestExtensionSystem::lazy_background_task_queue() {
   return NULL;
 }
 
-EventRouter* TestExtensionSystem::event_router() {
-  return NULL;
+void TestExtensionSystem::SetEventRouter(scoped_ptr<EventRouter> event_router) {
+  event_router_.reset(event_router.release());
 }
 
+EventRouter* TestExtensionSystem::event_router() { return event_router_.get(); }
+
 ExtensionWarningService* TestExtensionSystem::warning_service() {
   return NULL;
 }