[Extensions Bindings] Add a bindings/ subdirectory under renderer

extensions/renderer/bindings/declarative_event.h

Index: extensions/renderer/bindings/declarative_event.h
diff --git a/extensions/renderer/declarative_event.h b/extensions/renderer/bindings/declarative_event.h
similarity index 90%
rename from extensions/renderer/declarative_event.h
rename to extensions/renderer/bindings/declarative_event.h
index b0a7bcba7e130cda81c3012947b64137182dd8f2..5566fa889cbaf9b20cb09ec1031e966f6b940a8e 100644
--- a/extensions/renderer/declarative_event.h
+++ b/extensions/renderer/bindings/declarative_event.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef EXTENSIONS_RENDERER_DECLARATIVE_EVENT_H_
-#define EXTENSIONS_RENDERER_DECLARATIVE_EVENT_H_
+#ifndef EXTENSIONS_RENDERER_BINDINGS_DECLARATIVE_EVENT_H_
+#define EXTENSIONS_RENDERER_BINDINGS_DECLARATIVE_EVENT_H_
 
 #include <vector>
 
@@ -60,4 +60,4 @@ class DeclarativeEvent final : public gin::Wrappable<DeclarativeEvent> {
 
 }  // namespace extensions
 
-#endif  // EXTENSIONS_RENDERER_DECLARATIVE_EVENT_H_
+#endif  // EXTENSIONS_RENDERER_BINDINGS_DECLARATIVE_EVENT_H_