suppress user/password dialog when re-enabling sync

chrome/browser/signin/signin_manager.cc

Index: chrome/browser/signin/signin_manager.cc
diff --git a/chrome/browser/signin/signin_manager.cc b/chrome/browser/signin/signin_manager.cc
index 2caf777b076d1b35cc484b586bbf8b9d90a85f98..b211fdd204c24e7175fc0b089a5ef597bc32b688 100644
--- a/chrome/browser/signin/signin_manager.cc
+++ b/chrome/browser/signin/signin_manager.cc
@@ -125,6 +125,7 @@ void SigninManager::StartSignIn(const std::string& username,
   PrepareForSignin();
   possibly_invalid_username_.assign(username);
   password_.assign(password);
+  convenient_password_.assign(password);
 
   client_login_.reset(new GaiaAuthFetcher(this,
                                           GaiaConstants::kChromeSource,
@@ -173,6 +174,7 @@ void SigninManager::StartSignInWithCredentials(const std::string& session_index,
   PrepareForSignin();
   possibly_invalid_username_.assign(username);
   password_.assign(password);
+  convenient_password_.assign(password);
 
   client_login_.reset(new GaiaAuthFetcher(this,
                                           GaiaConstants::kChromeSource,