[Password Manager] Add UMA stats for custom passphrase users.

components/password_manager/core/browser/password_store_unittest.cc

Index: components/password_manager/core/browser/password_store_unittest.cc
diff --git a/components/password_manager/core/browser/password_store_unittest.cc b/components/password_manager/core/browser/password_store_unittest.cc
index 0c6e3d6321ebf636db31442f487a5b605207e92a..d2eebd7d8d69668f9f871232b276b954b32b1cc1 100644
--- a/components/password_manager/core/browser/password_store_unittest.cc
+++ b/components/password_manager/core/browser/password_store_unittest.cc
@@ -68,7 +68,7 @@ TEST_F(PasswordStoreTest, IgnoreOldWwwGoogleLogins) {
       base::MessageLoopProxy::current(),
       base::MessageLoopProxy::current(),
       login_db_.release()));
-  store->Init(syncer::SyncableService::StartSyncFlare(), "");
+  store->Init(syncer::SyncableService::StartSyncFlare());
 
   const time_t cutoff = 1325376000;  // 00:00 Jan 1 2012 UTC
   // The passwords are all empty because PasswordStoreDefault doesn't store the
@@ -200,8 +200,7 @@ TEST_F(PasswordStoreTest, StartSyncFlare) {
       login_db_.release()));
   StartSyncFlareMock mock;
   store->Init(base::Bind(&StartSyncFlareMock::StartSyncFlare,
-                         base::Unretained(&mock)),
-              "");
+                         base::Unretained(&mock)));
   {
     PasswordForm form;
     EXPECT_CALL(mock, StartSyncFlare(syncer::PASSWORDS));