Fix a typo in TwoWayServerAndLocalMerge

The test
PasswordSyncableServiceAndroidAutofillTest.TwoWayServerAndLocalMerge
derives a few parameters from a single integer variable in two places.
It seems that in the second place it prepares another variable to
derive from but then uses the same as in the first place. Looks like a
copy-paste typo. In any case, switching to the prepared variable has
strictly more coverage, so this CL changes to the prepared variable.

Bug: 739101
Change-Id: I27bb5895e48c1d1f87f91cac8a9e26fa81390e1d
Reviewed-on: https://chromium-review.googlesource.com/793610Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Vaclav Brozek <vabr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519837}

components/password_manager/core/browser/password_syncable_service_unittest.cc

@@ -1004,7 +1004,7 @@ TEST_F(PasswordSyncableServiceAndroidAutofillTest, TwoWayServerAndLocalMerge) {
     const bool local_data_correct = !!combination[1];
 
     for (unsigned val = 0; val < 2 * 2; ++val) {
-      std::vector<unsigned> dates = ExtractTimestamps(i, 2);
+      std::vector<unsigned> dates = ExtractTimestamps(val, 2);
       ASSERT_EQ(2u, dates.size());
 
       const PasswordFormData sync_data = sync_data_correct