[Extensions Bindings] Add a bindings/ subdirectory under renderer

extensions/renderer/bindings/argument_spec_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "extensions/renderer/argument_spec.h"
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
-#include "extensions/renderer/api_binding_test_util.h"
-#include "extensions/renderer/api_invocation_errors.h"
-#include "extensions/renderer/api_type_reference_map.h"
+#include "extensions/renderer/bindings/api_binding_test_util.h"
+#include "extensions/renderer/bindings/api_invocation_errors.h"
+#include "extensions/renderer/bindings/api_type_reference_map.h"
+#include "extensions/renderer/bindings/argument_spec.h"
 #include "gin/converter.h"
 #include "gin/public/isolate_holder.h"
 #include "gin/test/v8_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "v8/include/v8.h"
 
 namespace extensions {
 
 class ArgumentSpecUnitTest : public gin::V8Test {
  protected:
@@ skipping 787 matching lines @@
     std::vector<std::unique_ptr<ArgumentSpec>> choices;
     choices.push_back(base::MakeUnique<ArgumentSpec>(ArgumentType::INTEGER));
     choices.push_back(base::MakeUnique<ArgumentSpec>(ArgumentType::STRING));
     ArgumentSpec choices_spec(ArgumentType::CHOICES);
     choices_spec.set_choices(std::move(choices));
     EXPECT_EQ("[integer|string]", choices_spec.GetTypeName());
   }
 }
 
 }  // namespace extensions