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

chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.cc

Index: chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.cc
diff --git a/chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.cc b/chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.cc
index f26bc2eeba57775d9fb5d358be87d73307c2777e..d17567548cd99fdc32184ccade4b84288071acfd 100644
--- a/chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.cc
+++ b/chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.cc
@@ -8,9 +8,10 @@
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/sequenced_task_runner.h"
-#include "chrome/browser/extensions/api/storage/settings_backend.h"
+#include "chrome/browser/extensions/api/storage/local_storage_backend.h"
 #include "chrome/browser/extensions/api/storage/settings_frontend.h"
 #include "chrome/browser/extensions/api/storage/settings_storage_quota_enforcer.h"
+#include "chrome/browser/extensions/api/storage/sync_storage_backend.h"
 #include "chrome/browser/extensions/api/storage/weak_unlimited_settings_storage.h"
 #include "chrome/browser/sync/glue/sync_start_util.h"
 #include "content/public/browser/browser_thread.h"
@@ -47,16 +48,20 @@ SyncOrLocalValueStoreCache::~SyncOrLocalValueStoreCache() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 }
 
-SettingsBackend* SyncOrLocalValueStoreCache::GetAppBackend() const {
+syncer::SyncableService* SyncOrLocalValueStoreCache::GetSyncableService(
+    syncer::ModelType type) const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  DCHECK(app_backend_.get());
-  return app_backend_.get();
-}
-
-SettingsBackend* SyncOrLocalValueStoreCache::GetExtensionBackend() const {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  DCHECK(extension_backend_.get());
-  return extension_backend_.get();
+  switch (type) {
+    case syncer::APP_SETTINGS:
+      DCHECK(app_backend_.get());

[not at google - send to devlin, 2014/02/14 19:35:56]

all this DCHECK'ing of backends looks weird. Let's just have an |initialized_|
boolean.

[Devlin, 2014/02/18 23:55:22]

Done.

+      return app_backend_->GetAsSyncableService();
+    case syncer::EXTENSION_SETTINGS:
+      DCHECK(extension_backend_.get());
+      return extension_backend_->GetAsSyncableService();
+    default:
+      NOTREACHED();
+      return NULL;
+  }
 }
 
 void SyncOrLocalValueStoreCache::RunWithValueStoreForExtension(
@@ -102,20 +107,31 @@ void SyncOrLocalValueStoreCache::InitOnFileThread(
   DCHECK(!app_backend_.get());
   DCHECK(!extension_backend_.get());
   const bool local = settings_namespace_ == settings_namespace::LOCAL;

[not at google - send to devlin, 2014/02/14 19:35:56]

use switch

[Devlin, 2014/02/18 23:55:22]

Done.

-  const base::FilePath app_path = profile_path.AppendASCII(
-      local ? extensions::kLocalAppSettingsDirectoryName
-            : extensions::kSyncAppSettingsDirectoryName);
-  const base::FilePath extension_path = profile_path.AppendASCII(
-      local ? extensions::kLocalExtensionSettingsDirectoryName
-            : extensions::kSyncExtensionSettingsDirectoryName);
-  app_backend_.reset(new SettingsBackend(
-      factory, app_path, syncer::APP_SETTINGS,
-      sync_start_util::GetFlareForSyncableService(profile_path),
-      quota, observers));
-  extension_backend_.reset(new SettingsBackend(
-      factory, extension_path, syncer::EXTENSION_SETTINGS,
-      sync_start_util::GetFlareForSyncableService(profile_path),
-      quota, observers));
+  if (local) {
+    app_backend_.reset(new LocalStorageBackend(
+        factory,
+        profile_path.AppendASCII(kLocalAppSettingsDirectoryName),
+        quota));
+    extension_backend_.reset(new LocalStorageBackend(
+        factory,
+        profile_path.AppendASCII(kLocalExtensionSettingsDirectoryName),
+        quota));
+  } else {
+    app_backend_.reset(new SyncStorageBackend(
+        factory,
+        profile_path.AppendASCII(kSyncAppSettingsDirectoryName),
+        quota,
+        observers,
+        syncer::APP_SETTINGS,
+        sync_start_util::GetFlareForSyncableService(profile_path)));
+    extension_backend_.reset(new SyncStorageBackend(
+        factory,
+        profile_path.AppendASCII(kSyncExtensionSettingsDirectoryName),
+        quota,
+        observers,
+        syncer::EXTENSION_SETTINGS,
+        sync_start_util::GetFlareForSyncableService(profile_path)));
+  }
 }
 
 }  // namespace extensions