Extension settings API: send ACTION_UPDATE rather than ACTION_ADD when a

chrome/browser/extensions/extension_settings_sync_unittest.cc

Index: chrome/browser/extensions/extension_settings_sync_unittest.cc
diff --git a/chrome/browser/extensions/extension_settings_sync_unittest.cc b/chrome/browser/extensions/extension_settings_sync_unittest.cc
index 70734751c8fd71d3de9852dfff6e0c68f04e1608..43a50c0480f788ff58f83c9bf366156875004463 100644
--- a/chrome/browser/extensions/extension_settings_sync_unittest.cc
+++ b/chrome/browser/extensions/extension_settings_sync_unittest.cc
@@ -226,10 +226,22 @@ TEST_F(ExtensionSettingsSyncTest, InSyncDataDoesNotInvokeSync) {
 
   backend_->MergeDataAndStartSyncing(
       syncable::EXTENSION_SETTINGS, sync_data, &sync_);
-  backend_->StopSyncing(syncable::EXTENSION_SETTINGS);
 
   // Already in sync, so no changes.
   ASSERT_EQ(0u, sync_.changes().size());
+
+  // Regression test: not-changing the synced value shouldn't result in a sync
+  // change, and changing the synced value should result in an update.
+  storage1->Set("foo", value1);
+  ASSERT_EQ(0u, sync_.changes().size());
+
+  storage1->Set("foo", value2);
+  ASSERT_EQ(1u, sync_.changes().size());
+  ExtensionSettingSyncData change = sync_.GetOnlyChange("s1", "foo");
+  ASSERT_EQ(SyncChange::ACTION_UPDATE, change.change_type());
+  ASSERT_TRUE(value2.Equals(&change.value()));
+
+  backend_->StopSyncing(syncable::EXTENSION_SETTINGS);
 }
 
 TEST_F(ExtensionSettingsSyncTest, LocalDataWithNoSyncDataIsPushedToSync) {