Simulate transient error and verify exponential backoff.

chrome/test/live_sync/sync_errors_test.cc

Index: chrome/test/live_sync/sync_errors_test.cc
diff --git a/chrome/test/live_sync/sync_errors_test.cc b/chrome/test/live_sync/sync_errors_test.cc
index f062cca132d9a0ca8dfb48601c856f9e2553d32d..2c8ed254ba07ad18ea97927fc2deffaba4f0bad1 100644
--- a/chrome/test/live_sync/sync_errors_test.cc
+++ b/chrome/test/live_sync/sync_errors_test.cc
@@ -32,3 +32,18 @@ IN_PROC_BROWSER_TEST_F(SyncErrorTest, BirthdayErrorTest) {
   BookmarksHelper::SetTitle(0, node2, L"new_title2");
   ASSERT_TRUE(GetClient(0)->AwaitSyncDisabled("Birthday error."));
 }
+
+IN_PROC_BROWSER_TEST_F(SyncErrorTest, TransientErrorTest) {
+  ASSERT_TRUE(SetupSync()) << "SetupSync() failed.";
+
+  const BookmarkNode* node1 = BookmarksHelper::AddFolder(0, 0, L"title1");
+  BookmarksHelper::SetTitle(0, node1, L"new_title1");
+  ASSERT_TRUE(GetClient(0)->AwaitSyncCycleCompletion("Offline state change."));
+  TriggerTransientError();
+
+  // Now make one more change so we will do another sync.
+  const BookmarkNode* node2 = BookmarksHelper::AddFolder(0, 0, L"title2");
+  BookmarksHelper::SetTitle(0, node2, L"new_title2");
+  ASSERT_TRUE(
+      GetClient(0)->AwaitExponentialBackoffVerification());
+}