[bindings] Implement an ExperimentEnabled IDL extended attribute.

third_party/WebKit/Source/bindings/templates/methods.cpp

 {% from 'conversions.cpp' import declare_enum_validation_variable, v8_value_to_local_cpp_value %}
-
+{% from 'api_experiment.cpp' import check_api_experiment %}
 
 {##############################################################################}
 {% macro generate_method(method, world_suffix) %}
 {% filter conditional(method.conditional_string) %}
 {% if method.returns_promise and method.has_exception_state %}
 static void {{method.name}}{{method.overload_index}}Method{{world_suffix}}Promise(const v8::FunctionCallbackInfo<v8::Value>& info, ExceptionState& exceptionState)
 {% else %}
 static void {{method.name}}{{method.overload_index}}Method{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {% endif %}
 {
@@ skipping 491 matching lines @@
 static void {{method.name}}MethodCallback{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     TRACE_EVENT_SET_SAMPLING_STATE("blink", "DOMMethod");
     {% if not method.overloads %}{# Overloaded methods are measured in overload_resolution_method() #}
     {% if method.measure_as %}
     UseCounter::countIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::{{method.measure_as('Method')}});
     {% endif %}
     {% if method.deprecate_as %}
     UseCounter::countDeprecationIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::{{method.deprecate_as}});
     {% endif %}
+    {% filter trim %}
+    {{check_api_experiment(method) | indent}}
+    {% endfilter %}
     {% endif %}{# not method.overloads #}
     {% if world_suffix in method.activity_logging_world_list %}
     ScriptState* scriptState = ScriptState::from(info.GetIsolate()->GetCurrentContext());
     V8PerContextData* contextData = scriptState->perContextData();
     {% if method.activity_logging_world_check %}
     if (scriptState->world().isIsolatedWorld() && contextData && contextData->activityLogger())
     {% else %}
     if (contextData && contextData->activityLogger()) {
     {% endif %}
         ExceptionState exceptionState(ExceptionState::ExecutionContext, "{{method.name}}", "{{interface_name}}", info.Holder(), info.GetIsolate());
@@ skipping 183 matching lines @@
 {% filter runtime_enabled(method.overloads.runtime_enabled_function_all
                           if method.overloads else
                           method.runtime_enabled_function) %}
 const V8DOMConfiguration::MethodConfiguration {{method.name}}MethodConfiguration = {{method_configuration(method)}};
 V8DOMConfiguration::installMethod(isolate, v8::Local<v8::Object>(), prototypeObject, interfaceObject, defaultSignature, {{method.name}}MethodConfiguration);
 {% endfilter %}{# runtime_enabled() #}
 {% endfilter %}{# exposed() #}
 {% endfor %}
 {% endif %}
 {%- endmacro %}