[Extensions Bindings] Add Events support

extensions/renderer/api_binding.h

Index: extensions/renderer/api_binding.h
diff --git a/extensions/renderer/api_binding.h b/extensions/renderer/api_binding.h
index a1f8706603d89dbf29799d2331eeb1130292fbe2..01be5b1561304b0b3a75471606569738d9202f1f 100644
--- a/extensions/renderer/api_binding.h
+++ b/extensions/renderer/api_binding.h
@@ -25,6 +25,7 @@ class Arguments;
 }
 
 namespace extensions {
+class APIEventHandler;
 
 // A class that vends v8::Objects for extension APIs. These APIs have function
 // interceptors for all exposed methods, which call back into the APIBinding.
@@ -50,17 +51,20 @@ class APIBinding {
   using HandlerCallback = base::Callback<void(gin::Arguments*)>;
 
   // The ArgumentSpec::RefMap is required to outlive this object.
-  // |type_definitions| may be null if the API does not specify any types.
+  // |type_definitions| and |event_definitions| may be null if the API does not
+  // specify any types or events.
   APIBinding(const std::string& name,
              const base::ListValue& function_definitions,
              const base::ListValue* type_definitions,
+             const base::ListValue* event_definitions,
              const APIMethodCallback& callback,
              ArgumentSpec::RefMap* type_refs);
   ~APIBinding();
 
   // Returns a new v8::Object for the API this APIBinding represents.
   v8::Local<v8::Object> CreateInstance(v8::Local<v8::Context> context,
-                                       v8::Isolate* isolate);
+                                       v8::Isolate* isolate,
+                                       APIEventHandler* event_handler);
 
  private:
   using APISignature = std::vector<std::unique_ptr<ArgumentSpec>>;
@@ -87,6 +91,9 @@ class APIBinding {
   // A map from method name to expected signature.
   std::map<std::string, std::unique_ptr<APISignature>> signatures_;
 
+  // The names of all events associated with this API.
+  std::vector<std::string> event_names_;
+
   // The callback to use when an API is invoked with valid arguments.
   APIMethodCallback method_callback_;