IDL parser: Accept partial interface mixin

Before this CL, we took "partial interface mixin" a syntax error,
but Web IDL spec now accepts it to extend interface mixins.
This CL updates parser to accept it, and merges InterfaceMixin
class into Interface class.

Bug: 781257
Change-Id: I2b8584d5a1d4b8d2ffd53ba6a80c39e19feae11e
Reviewed-on: https://chromium-review.googlesource.com/1119744Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571808}

tools/idl_parser/idl_parser.py

@@ -307,14 +307,22 @@ class IDLParser(object):
     p[0] = self.BuildError(p, 'Partial')
 
   def p_PartialDefinition(self, p):
-    """PartialDefinition : PartialDictionary
-                         | PartialInterface
+    """PartialDefinition : INTERFACE PartialInterfaceOrPartialMixin
+                         | PartialDictionary
                          | Namespace"""
+    if len(p) > 2:
+      p[0] = p[2]
+    else:
+      p[0] = p[1]
+
+  def p_PartialInterfaceOrPartialMixin(self, p):
+    """PartialInterfaceOrPartialMixin : PartialInterfaceRest
+                                      | MixinRest"""
     p[0] = p[1]
 
-  def p_PartialInterface(self, p):
-    """PartialInterface : INTERFACE identifier '{' InterfaceMembers '}' ';'"""
-    p[0] = self.BuildNamed('Interface', p, 2, p[4])
+  def p_PartialInterfaceRest(self, p):
+    """PartialInterfaceRest : identifier '{' InterfaceMembers '}' ';'"""
+    p[0] = self.BuildNamed('Interface', p, 1, p[3])
 
   def p_InterfaceMembers(self, p):
     """InterfaceMembers : ExtendedAttributeList InterfaceMember InterfaceMembers
@@ -344,7 +352,8 @@ class IDLParser(object):
 
   def p_MixinRest(self, p):
     """MixinRest : MIXIN identifier '{' MixinMembers '}' ';'"""
-    p[0] = self.BuildNamed('InterfaceMixin', p, 2, p[4])
+    p[0] = self.BuildNamed('Interface', p, 2, p[4])
+    p[0].AddChildren(self.BuildTrue('MIXIN'))
 
   def p_MixinMembers(self, p):
     """MixinMembers : ExtendedAttributeList MixinMember MixinMembers

tools/idl_parser/test_parser/interface_web.idl

@@ -43,18 +43,24 @@ partial interface MyIFacePartial { };
 partial interface MyIFaceInherit : Foo {};
 
 /** TREE
- *InterfaceMixin(IFaceMixin)
+ *Interface(IFaceMixin)
+ *  MIXIN: True
  */
 interface mixin IFaceMixin {};
 
 /** ERROR Unexpected ":" after identifier "IFaceMixinInherit". */
 interface mixin IFaceMixinInherit : Foo {};
 
-/** ERROR Unexpected keyword "mixin" after keyword "interface". */
+/** TREE
+ *Interface(PartialIFaceMixin)
+ *  PARTIAL: True
+ *  MIXIN: True
+ */
 partial interface mixin PartialIFaceMixin {};
 
 /** TREE
- *InterfaceMixin(IFaceMixin)
+ *Interface(IFaceMixin)
+ *  MIXIN: True
  *  Error(Unexpected keyword "static" after "{".)
  */
 interface mixin IFaceMixin {
@@ -62,7 +68,8 @@ interface mixin IFaceMixin {
 };
 
 /** TREE
- *InterfaceMixin(IFaceMixin)
+ *Interface(IFaceMixin)
+ *  MIXIN: True
  *  Const(pi)
  *    PrimitiveType(double)
  *    Value() = "3.14159"