IDL compiler: Clean up Includes

Cleans up web_idl.Includes and completes its implementation
(by removing unused implementations).

Bug: 839389
Change-Id: I44cb8f04d1fdc34c6b7ddbded25f8d55193bda55
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1768597Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690284}

third_party/blink/renderer/bindings/scripts/web_idl/includes.py

@@ -2,10 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import exceptions
-
 from .composition_parts import Identifier
-from .composition_parts import WithCodeGeneratorInfo
 from .composition_parts import WithComponent
 from .composition_parts import WithDebugInfo
 from .identifier_ir_map import IdentifierIRMap
@@ -14,46 +11,29 @@ from .identifier_ir_map import IdentifierIRMap
 class Includes(WithComponent, WithDebugInfo):
     """https://heycam.github.io/webidl/#include"""
 
-    class IR(IdentifierIRMap.IR, WithCodeGeneratorInfo, WithComponent,
-             WithDebugInfo):
+    class IR(IdentifierIRMap.IR, WithComponent, WithDebugInfo):
         def __init__(self,
                      interface_identifier,
                      mixin_identifier,
-                     code_generator_info=None,
                      component=None,
                      debug_info=None):
             assert isinstance(interface_identifier, Identifier)
             assert isinstance(mixin_identifier, Identifier)
 
-            # Includes statements are treated similarly to partial
-            # definitions, and it's convenient for IdlCompiler that
-            # 'includes' are grouped by interface's identifier, i.e.
-            # a group of mixins are merged into the interface.
-            # So, we take the interface's identifier as this IR's
-            # identifier.
+            # Includes statements are treated similarly to partial definitions
+            # because it's convenient for IdlCompiler that 'includes' are
+            # grouped by interface's identifier, for example, a group of mixins
+            # are merged into an interface.  So, the interface's identifier is
+            # turned into this IR's identifier.
             IdentifierIRMap.IR.__init__(
                 self,
                 identifier=interface_identifier,
                 kind=IdentifierIRMap.IR.Kind.INCLUDES)
-            WithCodeGeneratorInfo.__init__(self, code_generator_info)
             WithComponent.__init__(self, component)
             WithDebugInfo.__init__(self, debug_info)
 
             self.interafce_identifier = interface_identifier
             self.mixin_identifier = mixin_identifier
 
-    @property
-    def interface(self):
-        """
-        Returns the interface that includes the mixin.
-        @return Interface
-        """
-        raise exceptions.NotImplementedError()
-
-    @property
-    def mixin(self):
-        """
-        Returns the interface mixin that is included by the other.
-        @return Interface
-        """
-        raise exceptions.NotImplementedError()
+    # Includes are not exposed publicly so far.
+    __init__ = None