Remove unnecessary 'virtual' annotation from mojo

mojo/public/tools/bindings/generators/cpp_templates/interface_definition.tmpl

 {%- import "interface_macros.tmpl" as interface_macros %}
 {%- import "struct_macros.tmpl" as struct_macros %}
 {%- set class_name = interface.name %}
 {%- set proxy_name = interface.name ~ "Proxy" %}
 {%- set namespace_as_string = "%s"|format(namespace|replace(".","::")) %}
 
 {%- macro alloc_params(struct) %}
 {%-   for param in struct.packed.packed_fields_in_ordinal_order %}
   {{param.field.kind|cpp_result_type}} p_{{param.field.name}}{};
 {%-   endfor %}
@@ skipping 28 matching lines @@
 {#--- ForwardToCallback definition #}
 {%- for method in interface.methods -%}
 {%-   if method.response_parameters != None %}
 class {{class_name}}_{{method.name}}_ForwardToCallback
     : public mojo::MessageReceiver {
  public:
   {{class_name}}_{{method.name}}_ForwardToCallback(
       const {{class_name}}::{{method.name}}Callback& callback)
       : callback_(callback) {
   }
-  virtual bool Accept(mojo::Message* message) override;
+  bool Accept(mojo::Message* message) override;
  private:
   {{class_name}}::{{method.name}}Callback callback_;
   MOJO_DISALLOW_COPY_AND_ASSIGN({{class_name}}_{{method.name}}_ForwardToCallback);
 };
 bool {{class_name}}_{{method.name}}_ForwardToCallback::Accept(
     mojo::Message* message) {
   internal::{{class_name}}_{{method.name}}_ResponseParams_Data* params =
       reinterpret_cast<internal::{{class_name}}_{{method.name}}_ResponseParams_Data*>(
           message->mutable_payload());
 
@@ skipping 62 matching lines @@
   }
 
   {{class_name}}_{{method.name}}_ProxyToResponder(
       uint64_t request_id,
       mojo::MessageReceiver* responder)
       : request_id_(request_id),
         responder_(responder),
         was_run_(false) {
   }
 
-  virtual void Run({{interface_macros.declare_params("in_", method.response_parameters)}}) const override;
+  void Run({{interface_macros.declare_params("in_", method.response_parameters)}}) const override;
 
  private:
   uint64_t request_id_;
   mutable mojo::MessageReceiver* responder_;
   mutable bool was_run_;
   MOJO_DISALLOW_COPY_AND_ASSIGN({{class_name}}_{{method.name}}_ProxyToResponder);
 };
 void {{class_name}}_{{method.name}}_ProxyToResponder::Run(
     {{interface_macros.declare_params("in_", method.response_parameters)}}) const {
   was_run_ = true;
@@ skipping 136 matching lines @@
       break;
     }
 {%-   endfor %}
   }
 {%- endif %}
 
   assert(sink_);
   return sink_->Accept(message);
 }
 {%- endif -%}