Add url/ to banned_directories in clang style checker.

tools/clang/plugins/ChromeClassTester.cpp

Index: tools/clang/plugins/ChromeClassTester.cpp
diff --git a/tools/clang/plugins/ChromeClassTester.cpp b/tools/clang/plugins/ChromeClassTester.cpp
index f23f6e2c7a38f684d169bbb9d2d128896c7bf9ae..5784334c2be3ed23197d4ca1a7d81ea8bb3111f8 100644
--- a/tools/clang/plugins/ChromeClassTester.cpp
+++ b/tools/clang/plugins/ChromeClassTester.cpp
@@ -36,9 +36,11 @@ bool ends_with(const std::string& one, const std::string& two) {
 
 }  // namespace
 
-ChromeClassTester::ChromeClassTester(CompilerInstance& instance)
+ChromeClassTester::ChromeClassTester(CompilerInstance& instance,
+                                     bool check_url_directory)
     : instance_(instance),
-      diagnostic_(instance.getDiagnostics()) {
+      diagnostic_(instance.getDiagnostics()),
+      check_url_directory_(check_url_directory) {
   BuildBannedLists();
 }
 
@@ -156,6 +158,9 @@ void ChromeClassTester::BuildBannedLists() {
   banned_directories_.push_back("icu4c/");
   banned_directories_.push_back("frameworks/");
 
+  if (!check_url_directory_)
+    banned_directories_.push_back("url/");
+
   // Don't check autogenerated headers.
   // Make puts them below $(builddir_name)/.../gen and geni.
   // Ninja puts them below OUTPUT_DIR/.../gen