[bindings] Implement an ExperimentEnabled IDL extended attribute.

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

Index: third_party/WebKit/Source/bindings/templates/methods.cpp
diff --git a/third_party/WebKit/Source/bindings/templates/methods.cpp b/third_party/WebKit/Source/bindings/templates/methods.cpp
index c9295cdb161dd59f47fef4cb27ac0742c9f17d09..2582c4d0c7b24d721b8605088be98500aeca6cd7 100644
--- a/third_party/WebKit/Source/bindings/templates/methods.cpp
+++ b/third_party/WebKit/Source/bindings/templates/methods.cpp
@@ -1,5 +1,5 @@
 {% 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) %}
@@ -511,6 +511,9 @@ static void {{method.name}}MethodCallback{{world_suffix}}(const v8::FunctionCall
     {% 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());