Introduce Promise mapping to the IDL generator

Source/bindings/scripts/code_generator_v8.py

Index: Source/bindings/scripts/code_generator_v8.py
diff --git a/Source/bindings/scripts/code_generator_v8.py b/Source/bindings/scripts/code_generator_v8.py
index 0e647b49f749dc6951e431c48ed5340f24398a0a..1231a5bb49256d06b62f84c78d8d02bf015a0395 100644
--- a/Source/bindings/scripts/code_generator_v8.py
+++ b/Source/bindings/scripts/code_generator_v8.py
@@ -84,6 +84,7 @@ CPP_TYPE_SPECIAL_CONVERSION_RULES = {
     'byte': 'int',
     'boolean': 'bool',
     'DOMString': 'const String&',
+    'Promise': 'ScriptPromise',
 }
 CPP_UNSIGNED_TYPES = set([
     'octet',
@@ -91,10 +92,13 @@ CPP_UNSIGNED_TYPES = set([
     'unsigned long',
     'unsigned short',
 ])
+# Promise is not yet in the Web IDL spec but is going to be speced
+# as primitive types in the future.
 PRIMITIVE_TYPES = set([
     'boolean',
     'void',
     'Date',
+    'Promise',
     'byte',
     'octet',
     'short',
@@ -211,6 +215,8 @@ def uncapitalize(name):
 def includes_for_type(data_type):
     if primitive_type(data_type) or data_type == 'DOMString':
         return set()
+    if data_type == 'Promise':
+        return set(['ScriptPromise.h'])
     if array_or_sequence_type(data_type):
         return includes_for_type(array_or_sequence_type(data_type))
     return set(['V8%s.h' % data_type])