IDL: Drop [PerContextEnabled] extended attribute

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 b525d21d3a22b6009b9977295bb675b24ba49ec7..90efcc7f03f5d1df36281341a03c9963d019c407 100644
--- a/Source/bindings/scripts/code_generator_v8.py
+++ b/Source/bindings/scripts/code_generator_v8.py
@@ -387,7 +387,6 @@ def initialize_jinja_env(cache_dir):
         'blink_capitalize': capitalize,
         'conditional': conditional_if_endif,
         'exposed': exposed_if,
-        'per_context_enabled': per_context_enabled_if,
         'runtime_enabled': runtime_enabled_if,
         })
     return jinja_env
@@ -418,13 +417,6 @@ def exposed_if(code, exposed_test):
     return generate_indented_conditional(code, 'context && (%s)' % exposed_test)
 
 
-# [PerContextEnabled]
-def per_context_enabled_if(code, per_context_enabled_function):
-    if not per_context_enabled_function:
-        return code
-    return generate_indented_conditional(code, 'context && context->isDocument() && %s(toDocument(context))' % per_context_enabled_function)
-
-
 # [RuntimeEnabled]
 def runtime_enabled_if(code, runtime_enabled_function_name):
     if not runtime_enabled_function_name: