Sync polling tests: Set poll interval prefs before starting sync

Setting the prefs has no immediate effect - they're only read during
sync startup (and after that, there are many situations where the values
are overwritten).

https://crrev.com/c/1148392 exposed this as an actual problem; before
that, things just happened to work out.

Bug: 856179
Change-Id: I24a3c8a22c87a128238efb5d0b9dd2ef8a022c71
Reviewed-on: https://chromium-review.googlesource.com/1156600Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579776}

chrome/browser/sync/test/integration/single_client_polling_sync_test.cc

@@ -108,7 +108,15 @@ IN_PROC_BROWSER_TEST_F(SingleClientPollingSyncTest,
 IN_PROC_BROWSER_TEST_F(SingleClientPollingSyncTest,
                        ShouldPollWhenIntervalExpiredAcrossRestarts) {
   base::Time start = base::Time::Now();
+
+  ASSERT_TRUE(SetupClients()) << "SetupClients() failed.";
+
+  SyncPrefs remote_prefs(GetProfile(0)->GetPrefs());
+  remote_prefs.SetShortPollInterval(base::TimeDelta::FromMinutes(10));
+  remote_prefs.SetLongPollInterval(base::TimeDelta::FromMinutes(10));
+
   ASSERT_TRUE(SetupSync()) << "SetupSync() failed.";
+
   // Trigger a sync-cycle.
   ASSERT_TRUE(CheckInitialState(0));
   ASSERT_TRUE(OpenTab(0, GURL(chrome::kChromeUIHistoryURL)));
@@ -119,7 +127,6 @@ IN_PROC_BROWSER_TEST_F(SingleClientPollingSyncTest,
                   .Wait());
 
   // Verify that the last poll time got initialized to a reasonable value.
-  SyncPrefs remote_prefs(GetProfile(0)->GetPrefs());
   EXPECT_THAT(remote_prefs.GetLastPollTime(), Ge(start));
   EXPECT_THAT(remote_prefs.GetLastPollTime(), Le(base::Time::Now()));
 
@@ -129,8 +136,6 @@ IN_PROC_BROWSER_TEST_F(SingleClientPollingSyncTest,
   GetClient(0)->StopSyncService(syncer::SyncService::KEEP_DATA);
 
   // Simulate elapsed time so that the poll interval expired.
-  remote_prefs.SetShortPollInterval(base::TimeDelta::FromMinutes(10));
-  remote_prefs.SetLongPollInterval(base::TimeDelta::FromMinutes(10));
   remote_prefs.SetLastPollTime(base::Time::Now() -
                                base::TimeDelta::FromMinutes(11));
   ASSERT_TRUE(GetClient(0)->StartSyncService()) << "SetupSync() failed.";

chrome/browser/sync/test/integration/two_client_polling_sync_test.cc

@@ -68,6 +68,13 @@ class SessionCountMatchChecker : public SingleClientStatusChangeChecker {
 // data from client 0. That second phase will rely on polling on client 1 to
 // receive the update.
 IN_PROC_BROWSER_TEST_F(TwoClientPollingSyncTest, ShouldPollOnStartup) {
+  ASSERT_TRUE(SetupClients()) << "SetupClients() failed.";
+
+  // Choose larger intervals to verify the poll-on-start logic.
+  SyncPrefs remote_prefs(GetProfile(1)->GetPrefs());
+  remote_prefs.SetShortPollInterval(base::TimeDelta::FromMinutes(2));
+  remote_prefs.SetLongPollInterval(base::TimeDelta::FromMinutes(2));
+
   ASSERT_TRUE(SetupSync()) << "SetupSync() failed.";
 
   // Phase 1.
@@ -92,11 +99,7 @@ IN_PROC_BROWSER_TEST_F(TwoClientPollingSyncTest, ShouldPollOnStartup) {
   // Now start up the remote client (make sure it should start a poll after
   // start-up) and verify it receives the latest changes and the poll cycle
   // updated the last-poll-time.
-  // All data is already there, so we can get it in the first poll. Choose
-  // larger intervals to verify the poll-on-start logic.
-  SyncPrefs remote_prefs(GetProfile(1)->GetPrefs());
-  remote_prefs.SetShortPollInterval(base::TimeDelta::FromMinutes(2));
-  remote_prefs.SetLongPollInterval(base::TimeDelta::FromMinutes(2));
+  // All data is already there, so we can get it in the first poll.
   base::Time remote_start = base::Time::Now();
   base::Time new_last_poll_time = base::Time::Now() -
                                   base::TimeDelta::FromMinutes(2) -