Start the migration of passwords from the Keychain.

chrome/browser/password_manager/simple_password_store_mac.h

Index: chrome/browser/password_manager/simple_password_store_mac.h
diff --git a/chrome/browser/password_manager/simple_password_store_mac.h b/chrome/browser/password_manager/simple_password_store_mac.h
index 3e046b9ea4369df836d266eab9814fbb48071cec..541e69f4e3692536d48134a94128c9240746a5e3 100644
--- a/chrome/browser/password_manager/simple_password_store_mac.h
+++ b/chrome/browser/password_manager/simple_password_store_mac.h
@@ -16,9 +16,11 @@ class SimplePasswordStoreMac : public password_manager::PasswordStoreDefault {
       scoped_refptr<base::SingleThreadTaskRunner> background_thread_runner,

[vabr (Chromium), 2015/07/03 08:40:48]

nit: Passing of background runners both in the constructor and in
InitWithTaskRunner deserves an explanation in a comment. Alternatively, if it
always passes nullptr to PasswordStoreDefault, then we should drop it as the
argument and just hard-code nullptr to the call to PasswordStoreDefault's
constructor.

[vasilii, 2015/07/03 12:59:11]

Done. I use both null and non-null calls.

       scoped_ptr<password_manager::LoginDatabase> login_db);
 
-  // Just hides the parent method. All the initialization is to be done by
-  // PasswordStoreProxyMac that is an owner of the class.
-  bool Init(const syncer::SyncableService::StartSyncFlare& flare) override;
+  // Sets the background thread and LoginDatabase. |login_db| should be already
+  // inited.
+  void InitWithTaskRunner(
+      scoped_refptr<base::SingleThreadTaskRunner> background_task_runner,
+      scoped_ptr<password_manager::LoginDatabase> login_db);
 
   // Clean |background_thread_runner_|.
   void Shutdown() override;
@@ -29,6 +31,8 @@ class SimplePasswordStoreMac : public password_manager::PasswordStoreDefault {
   ~SimplePasswordStoreMac() override;
 
  private:
+  using PasswordStoreDefault::Init;

[vabr (Chromium), 2015/07/03 08:40:48]

Please remind me: where is this called from?

[vasilii, 2015/07/03 12:59:11]

It's not called, that's why it's private.

[vabr (Chromium), 2015/07/06 09:50:19]

Fair enough. But if you want to avoid people calling Init on
SimplePasswordStoreMac by accident, I would suggest actually providing an
implementation and putting NOTREACHED() in it. This way one can still call
Init() through down-casting the store's pointer. The private + using hint may be
too subtle and get missed, whereas a NOTREACHED() is a clear statement.

[vasilii, 2015/07/06 13:57:57]

Done.

+
   DISALLOW_COPY_AND_ASSIGN(SimplePasswordStoreMac);
 };