IDL: Drop value conversion (V8 -> C++) macros from generated code

Source/bindings/templates/dictionary_v8.cpp

Index: Source/bindings/templates/dictionary_v8.cpp
diff --git a/Source/bindings/templates/dictionary_v8.cpp b/Source/bindings/templates/dictionary_v8.cpp
index 084666b692998a55a5ea7e8cd85947ac8dae48ee..54ae4ec7df558053aa63a1935fbead65b6ddc934 100644
--- a/Source/bindings/templates/dictionary_v8.cpp
+++ b/Source/bindings/templates/dictionary_v8.cpp
@@ -15,23 +15,23 @@ namespace blink {
 
 {% macro convert_and_set_member(member) %}
 {% endmacro %}
-void {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8Value, {{cpp_class}}& impl, ExceptionState& exceptionState)
+bool {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8Value, {{cpp_class}}& impl, ExceptionState& exceptionState)
 {
     if (isUndefinedOrNull(v8Value))
-        return;
+        return true;
     if (!v8Value->IsObject()) {
         {% if use_permissive_dictionary_conversion %}
         // Do nothing.
+        return true;
         {% else %}
         exceptionState.throwTypeError("cannot convert to dictionary.");
+        return false;
         {% endif %}
-        return;
     }
 
     {% if parent_v8_class %}
-    {{parent_v8_class}}::toImpl(isolate, v8Value, impl, exceptionState);
-    if (exceptionState.hadException())
-        return;
+    if (!{{parent_v8_class}}::toImpl(isolate, v8Value, impl, exceptionState))
+        return false;
 
     {% endif %}
     {# Declare local variables only when the dictionary has members to avoid unused variable warnings. #}
@@ -43,7 +43,7 @@ void {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8Value, {{
     v8::Local<v8::Value> {{member.name}}Value = v8Object->Get(v8String(isolate, "{{member.name}}"));
     if (block.HasCaught()) {
         exceptionState.rethrowV8Exception(block.Exception());
-        return;
+        return false;
     }
     if ({{member.name}}Value.IsEmpty() || {{member.name}}Value->IsUndefined()) {
         // Do nothing.
@@ -55,32 +55,30 @@ void {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8Value, {{
         {% if member.deprecate_as %}
         UseCounter::countDeprecationIfNotPrivateScript(isolate, callingExecutionContext(isolate), UseCounter::{{member.deprecate_as}});
         {% endif %}
-        {% if member.use_output_parameter_for_result %}
-        {{member.cpp_type}} {{member.name}};
-        {% endif %}
         {{member.v8_value_to_local_cpp_value}};
         {% if member.is_interface_type %}
         if (!{{member.name}} && !{{member.name}}Value->IsNull()) {
             exceptionState.throwTypeError("member {{member.name}} is not of type {{member.idl_type}}.");
-            return;
+            return false;
         }
         {% endif %}
         {% if member.enum_validation_expression %}
         String string = {{member.name}};
         if (!({{member.enum_validation_expression}})) {
             exceptionState.throwTypeError("member {{member.name}} ('" + string + "') is not a valid enum value.");
-            return;
+            return false;
         }
         {% elif member.is_object %}
         if (!{{member.name}}.isObject()) {
             exceptionState.throwTypeError("member {{member.name}} is not an object.");
-            return;
+            return false;
         }
         {% endif %}
         impl.{{member.setter_name}}({{member.name}});
     }
 
     {% endfor %}
+    return true;
 }
 
 v8::Local<v8::Value> toV8(const {{cpp_class}}& impl, v8::Local<v8::Object> creationContext, v8::Isolate* isolate)