[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..f6c0ff4306edc26d4a600f1d99690d2bd7766969 100644
--- a/third_party/WebKit/Source/bindings/templates/methods.cpp
+++ b/third_party/WebKit/Source/bindings/templates/methods.cpp
@@ -366,7 +366,7 @@ createMinimumArityTypeErrorForMethod(info.GetIsolate(), "{{method.name}}", "{{in
 static int {{overloads.name}}MethodLength()
 {
     {% for length, runtime_enabled_functions in overloads.runtime_determined_lengths %}
-    {% for runtime_enabled_function in runtime_enabled_functions %}
+{% for runtime_enabled_function in runtime_enabled_functions %}
     {% filter runtime_enabled(runtime_enabled_function) %}
     return {{length}};
     {% endfilter %}
@@ -398,6 +398,8 @@ we must ensure either ALL or NO methods in this overload return Promise #}
 {% macro overload_resolution_method(overloads, world_suffix) %}
 static void {{overloads.name}}Method{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
+    String errorMessage;
+    ALLOW_UNUSED_LOCAL(errorMessage);
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "{{overloads.name}}", "{{interface_name}}", info.Holder(), info.GetIsolate());
     {% if overloads.measure_all_as %}
     UseCounter::countIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::{{overloads.measure_all_as}});
@@ -417,6 +419,8 @@ static void {{overloads.name}}Method{{world_suffix}}(const v8::FunctionCallbackI
         {% if method.visible %}
         {% filter runtime_enabled(not overloads.runtime_enabled_function_all and
                                   method.runtime_enabled_function) %}
+        {% filter experiment_enabled(not overloads.experimental_api_name_all and
+                                     method.experimental_api_name, "errorMessage") %}
         if ({{test}}) {
             {% if method.measure_as and not overloads.measure_all_as %}
             UseCounter::countIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::{{method.measure_as('Method')}});
@@ -428,6 +432,7 @@ static void {{overloads.name}}Method{{world_suffix}}(const v8::FunctionCallbackI
             return;
         }
         {% endfilter %}
+        {% endfilter %}
         {% endif %}
         {% endfor %}
         break;
@@ -700,6 +705,8 @@ V8DOMConfiguration::installMethod(isolate, {{instance_template}}, {{prototype_te
 v8::Local<v8::Signature> defaultSignature = v8::Signature::New(isolate, domTemplate(isolate));
 ExecutionContext* executionContext = toExecutionContext(prototypeObject->CreationContext());
 ASSERT(executionContext);
+String errorMessage;
+ALLOW_UNUSED_LOCAL(errorMessage);
 {% for method in conditionally_enabled_methods %}
 {% filter exposed(method.overloads.exposed_test_all
                   if method.overloads else
@@ -707,8 +714,12 @@ ASSERT(executionContext);
 {% filter runtime_enabled(method.overloads.runtime_enabled_function_all
                           if method.overloads else
                           method.runtime_enabled_function) %}
+{% filter experiment_enabled(method.overloads.experimental_api_name_all
+                        if method.overloads else
+                        method.experimental_api_name, "errorMessage") %}
 const V8DOMConfiguration::MethodConfiguration {{method.name}}MethodConfiguration = {{method_configuration(method)}};
 V8DOMConfiguration::installMethod(isolate, v8::Local<v8::Object>(), prototypeObject, interfaceObject, defaultSignature, {{method.name}}MethodConfiguration);
+{% endfilter %}{# experiment_enabled() #}
 {% endfilter %}{# runtime_enabled() #}
 {% endfilter %}{# exposed() #}
 {% endfor %}