[Sync] Add an error integration test for USS.

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

Index: chrome/browser/sync/test/integration/two_client_uss_sync_test.cc
diff --git a/chrome/browser/sync/test/integration/two_client_uss_sync_test.cc b/chrome/browser/sync/test/integration/two_client_uss_sync_test.cc
index b9df9538c0d7a1787998a90d1c71916cec9d5e10..1b56a7d6e6331e0dc2d63376cfb3b10003baea2b 100644
--- a/chrome/browser/sync/test/integration/two_client_uss_sync_test.cc
+++ b/chrome/browser/sync/test/integration/two_client_uss_sync_test.cc
@@ -8,6 +8,7 @@
 #include "chrome/browser/sync/chrome_sync_client.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
 #include "chrome/browser/sync/test/integration/profile_sync_service_harness.h"
+#include "chrome/browser/sync/test/integration/single_client_status_change_checker.h"
 #include "chrome/browser/sync/test/integration/status_change_checker.h"
 #include "chrome/browser/sync/test/integration/sync_integration_test_util.h"
 #include "chrome/browser/sync/test/integration/sync_test.h"
@@ -23,6 +24,7 @@ using syncer_v2::ModelTypeService;
 using syncer_v2::SharedModelTypeProcessor;
 
 const char kKey1[] = "key1";
+const char kKey2[] = "key2";
 const char kValue1[] = "value1";
 const char kValue2[] = "value2";
 const char kValue3[] = "value3";
@@ -90,7 +92,6 @@ class KeyChecker : public StatusChangeChecker,
  public:
   KeyChecker(TestModelTypeService* service, const std::string& key)
       : service_(service), key_(key) {}
-  ~KeyChecker() override {}
 
   void OnApplySyncChanges() override { CheckExitCondition(); }
 
@@ -118,7 +119,6 @@ class DataChecker : public KeyChecker {
               const std::string& key,
               const std::string& value)
       : KeyChecker(service, key), value_(value) {}
-  ~DataChecker() override {}
 
   bool IsExitConditionSatisfied() override {
     const auto& db = service_->db();
@@ -138,7 +138,6 @@ class DataAbsentChecker : public KeyChecker {
  public:
   DataAbsentChecker(TestModelTypeService* service, const std::string& key)
       : KeyChecker(service, key) {}
-  ~DataAbsentChecker() override {}
 
   bool IsExitConditionSatisfied() override {
     return !service_->db().HasData(key_);
@@ -154,7 +153,6 @@ class MetadataPresentChecker : public KeyChecker {
  public:
   MetadataPresentChecker(TestModelTypeService* service, const std::string& key)
       : KeyChecker(service, key) {}
-  ~MetadataPresentChecker() override {}
 
   bool IsExitConditionSatisfied() override {
     return service_->db().HasMetadata(key_);
@@ -170,7 +168,6 @@ class MetadataAbsentChecker : public KeyChecker {
  public:
   MetadataAbsentChecker(TestModelTypeService* service, const std::string& key)
       : KeyChecker(service, key) {}
-  ~MetadataAbsentChecker() override {}
 
   bool IsExitConditionSatisfied() override {
     return !service_->db().HasMetadata(key_);
@@ -181,6 +178,26 @@ class MetadataAbsentChecker : public KeyChecker {
   }
 };
 
+// Wait for PREFERENCES to no longer be running.
+class PrefsNotRunningChecker : public SingleClientStatusChangeChecker {
+ public:
+  explicit PrefsNotRunningChecker(browser_sync::ProfileSyncService* service)
+      : SingleClientStatusChangeChecker(service) {}
+
+  bool Wait() {
+    SingleClientStatusChangeChecker::Wait();
+    return !TimedOut();
+  }
+
+  bool IsExitConditionSatisfied() override {
+    return !service()->IsDataTypeControllerRunning(syncer::PREFERENCES);
+  }
+
+  std::string GetDebugMessage() const override {
+    return "Waiting for prefs to be not running.";
+  }
+};
+
 class TwoClientUssSyncTest : public SyncTest {
  public:
   TwoClientUssSyncTest() : SyncTest(TWO_CLIENT) {
@@ -301,3 +318,23 @@ IN_PROC_BROWSER_TEST_F(TwoClientUssSyncTest, ConflictResolution) {
   ASSERT_TRUE(DataChecker(model1, kKey1, kValue3).Wait());
   ASSERT_TRUE(DataChecker(model2, kKey1, kValue3).Wait());
 }
+
+IN_PROC_BROWSER_TEST_F(TwoClientUssSyncTest, Error) {
+  ASSERT_TRUE(SetupSync());
+  TestModelTypeService* model1 = GetModelTypeService(0);
+  TestModelTypeService* model2 = GetModelTypeService(1);
+
+  // Add an entity.
+  model1->WriteItem(kKey1, kValue1);
+  ASSERT_TRUE(DataChecker(model2, kKey1, kValue1).Wait());
+
+  // Queue an error in model 2 and trigger a GetUpdates.

[skym, 2016/09/28 21:53:34]

As we talked about offline, expand this comment to include all the middle steps
and causes.

[maxbogue, 2016/09/28 22:36:30]

Done.

+  model2->SetServiceError(syncer::SyncError::DATATYPE_ERROR);
+  model1->WriteItem(kKey1, kValue2);
+
+  // The type should stop syncing but keep tracking metadata.
+  ASSERT_TRUE(PrefsNotRunningChecker(GetSyncService(1)).Wait());
+  ASSERT_EQ(1U, model2->db().metadata_count());
+  model2->WriteItem(kKey2, kValue2);
+  ASSERT_EQ(2U, model2->db().metadata_count());
+}