Add extended attribute, [Measure], to simplify use counting

Source/bindings/templates/methods.cpp

 {##############################################################################}
 {% macro generate_method(method, world_suffix) %}
 {% filter conditional(method.conditional_string) %}
 static void {{method.name}}{{method.overload_index}}Method{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     {# Local variables #}
     {% if method.has_exception_state %}
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "{{method.name}}", "{{interface_name}}", info.Holder(), info.GetIsolate());
     {% endif %}
     {# Overloaded methods have length checked during overload resolution #}
@@ skipping 357 matching lines @@
     {% for length, tests_methods in overloads.length_tests_methods %}
     {# 10. If i = d, then: #}
     case {{length}}:
         {# Then resolve by testing argument #}
         {% for test, method in tests_methods %}
         {% if method.visible %}
         {% filter runtime_enabled(not overloads.runtime_enabled_function_all and
                                   method.runtime_enabled_function) %}
         if ({{test}}) {
             {% if method.measure_as and not overloads.measure_all_as %}
-            UseCounter::countIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::{{method.measure_as}});
+            UseCounter::countIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::{{method.measure_as('Overload%d' % method.overload_index)}});

[Jens Widell, 2015/01/26 07:14:48]

This seems somewhat problematic to me; what a method is measured as depends
implicitly on otherwise irrelevant details in the IDL file, like order, and may
change if the order is changed or if overloads are added or removed. It'd be
difficult to keep track of what each counter actually means over time.

I think I'd prefer if overloads were simply measured as "Method" unless you put
specific [MeasureAs] attributes (with actual names describing the overload,
instead of indexes) on the different method definitions.

[dstockwell, 2015/01/26 07:26:48]

That seems a reasonable solution for overloads. Changed to that behavior.

             {% endif %}
             {% if method.deprecate_as and not overloads.deprecate_all_as %}
             UseCounter::countDeprecationIfNotPrivateScript(info.GetIsolate(), callingExecutionContext(info.GetIsolate()), UseCounter::{{method.deprecate_as}});
             {% endif %}
             {{method.name}}{{method.overload_index}}Method{{world_suffix}}(info);
             return;
         }
         {% endfilter %}
         {% endif %}
         {% endfor %}
@@ skipping 38 matching lines @@
 
 
 {##############################################################################}
 {% macro method_callback(method, world_suffix) %}
 {% filter conditional(method.conditional_string) %}
 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}});
+    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 %}
     {% 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())
@@ skipping 203 matching lines @@
                               if method.overloads else
                               method.runtime_enabled_function) %}
     prototypeObject->Set(v8AtomicString(isolate, "{{method.name}}"), v8::FunctionTemplate::New(isolate, {{cpp_class_or_partial}}V8Internal::{{method.name}}MethodCallback, v8Undefined(), defaultSignature, {{method.number_of_required_arguments}})->GetFunction());
     {% endfilter %}{# runtime_enabled() #}
     {% endfilter %}{# exposed() #}
     {% endfilter %}{# per_context_enabled() #}
     {% endfor %}
     {% endif %}
 }
 {%- endmacro %}