Migrate data from old localstorage format to new format.

content/browser/dom_storage/local_storage_context_mojo.h

Index: content/browser/dom_storage/local_storage_context_mojo.h
diff --git a/content/browser/dom_storage/local_storage_context_mojo.h b/content/browser/dom_storage/local_storage_context_mojo.h
index 6806302805ffbf4d11134bcb60da4e255ce6407d..b3deb4ef86ee38a1699f6d37a64fd0dc7144071e 100644
--- a/content/browser/dom_storage/local_storage_context_mojo.h
+++ b/content/browser/dom_storage/local_storage_context_mojo.h
@@ -20,6 +20,7 @@ class Connector;
 
 namespace content {
 
+class DOMStorageTaskRunner;
 class LevelDBWrapperImpl;
 struct LocalStorageUsageInfo;
 
@@ -31,6 +32,8 @@ class CONTENT_EXPORT LocalStorageContextMojo {
       base::OnceCallback<void(std::vector<LocalStorageUsageInfo>)>;
 
   LocalStorageContextMojo(service_manager::Connector* connector,
+                          scoped_refptr<DOMStorageTaskRunner> task_runner,
+                          const base::FilePath& old_localstorage_path,
                           const base::FilePath& subdirectory);
   ~LocalStorageContextMojo();
 
@@ -45,15 +48,13 @@ class CONTENT_EXPORT LocalStorageContextMojo {
   leveldb::mojom::LevelDBDatabaseAssociatedRequest DatabaseRequestForTesting();
 
  private:
+  class LevelDBWrapperHolder;
+
   // Runs |callback| immediately if already connected to a database, otherwise
   // delays running |callback| untill after a connection has been established.
   // Initiates connecting to the database if no connection is in progres yet.
   void RunWhenConnected(base::OnceClosure callback);
 
-  void OnLevelDBWrapperHasNoBindings(const url::Origin& origin);
-  std::vector<leveldb::mojom::BatchedOperationPtr>
-  OnLevelDBWrapperPrepareToCommit(const url::Origin& origin,
-                                  const LevelDBWrapperImpl& wrapper);
   void OnUserServiceConnectionComplete();
   void OnUserServiceConnectionError();
 
@@ -107,7 +108,12 @@ class CONTENT_EXPORT LocalStorageContextMojo {
   std::vector<base::OnceClosure> on_database_opened_callbacks_;
 
   // Maps between an origin and its prefixed LevelDB view.
-  std::map<url::Origin, std::unique_ptr<LevelDBWrapperImpl>> level_db_wrappers_;
+  std::map<url::Origin, std::unique_ptr<LevelDBWrapperHolder>>
+      level_db_wrappers_;
+
+  // Used to access old data for migration.
+  scoped_refptr<DOMStorageTaskRunner> task_runner_;
+  base::FilePath old_localstorage_path_;
 
   base::WeakPtrFactory<LocalStorageContextMojo> weak_ptr_factory_;
 };