Revert of clang plugin: Remove check-templates toggle.

tools/clang/plugins/FindBadConstructsAction.cpp

Index: tools/clang/plugins/FindBadConstructsAction.cpp
diff --git a/tools/clang/plugins/FindBadConstructsAction.cpp b/tools/clang/plugins/FindBadConstructsAction.cpp
index 7458c543c7dccfee867a87d6bbb28337cd6f7e5e..4ef49a1d17389a219543e1188145ec17c4c8f04e 100644
--- a/tools/clang/plugins/FindBadConstructsAction.cpp
+++ b/tools/clang/plugins/FindBadConstructsAction.cpp
@@ -56,8 +56,7 @@
       // and http://crbug.com/356816 are fixed.
       options_.check_enum_last_value = true;
     } else if (args[i] == "check-templates") {
-      // TODO(thakis): This is now always on. Remove support for this flag once
-      // the build no longer passes it in.
+      options_.check_templates = true;
     } else if (args[i] == "follow-macro-expansion") {
       // TODO(thakis): This is now always on. Remove support for this flag once
       // the build no longer passes it in.