Make the "Tabs" item on about:sync non-yellow

sync/syncable/model_type_unittest.cc

Index: sync/syncable/model_type_unittest.cc
diff --git a/sync/syncable/model_type_unittest.cc b/sync/syncable/model_type_unittest.cc
index 7bf50e55ed84f418d7935d0616ce711102498431..2869f315f5617e286fe3908d7dd40f016b6b95fe 100644
--- a/sync/syncable/model_type_unittest.cc
+++ b/sync/syncable/model_type_unittest.cc
@@ -71,6 +71,12 @@ TEST_F(ModelTypeTest, IsRealDataType) {
   EXPECT_TRUE(IsRealDataType(APPS));
 }
 
+TEST_F(ModelTypeTest, IsProxyType) {
+  EXPECT_FALSE(IsProxyType(BOOKMARKS));
+  EXPECT_FALSE(IsProxyType(MODEL_TYPE_COUNT));
+  EXPECT_TRUE(IsProxyType(PROXY_TABS));
+}
+
 // Make sure we can convert ModelTypes to and from specifics field
 // numbers.
 TEST_F(ModelTypeTest, ModelTypeToFromSpecificsFieldNumber) {