Introduce [Exposed(Arguments)] in IDL code generator.

Source/bindings/scripts/generate_global_constructors.py

Index: Source/bindings/scripts/generate_global_constructors.py
diff --git a/Source/bindings/scripts/generate_global_constructors.py b/Source/bindings/scripts/generate_global_constructors.py
index 1be2ac3327c730f529759f552f658bfeff42f7c5..a6c8598a0f050652113da52d6bda2dec86a22c16 100755
--- a/Source/bindings/scripts/generate_global_constructors.py
+++ b/Source/bindings/scripts/generate_global_constructors.py
@@ -87,6 +87,10 @@ def record_global_constructors(idl_filename):
     # associated with ECMAScript global environments whose global object
     # implements an interface that has a matching global name.
     exposed_global_names = extended_attributes.get('Exposed', 'Window').strip('()').split(',')

[Jens Widell, 2014/12/09 08:25:12]

Does this really work now? It doesn't look like
get_interface_extended_attributes_from_idl() can quite cope with extended
attributes using the Name(Arguments) syntax.

Can you update a test IDL file to use the new syntax for an interface's Exposed?

[yhirano, 2014/12/09 08:42:09]

Yeah, I fixed this script in another
CL(https://codereview.chromium.org/771323004/).
I added Exposed(Arguments) in TestInterface2.idl, but it doesn't have any
effect.

[Jens Widell, 2014/12/09 09:20:47]

It would make sense to move that fix over from that CL to this, I think.

+    # Blink has Exposed(Arguments) form. In the form, each argument type
+    # represents the global context.
+    exposed_global_names = [name.split(' ')[0] for name in exposed_global_names]
+
     new_constructors_list = generate_global_constructors_list(interface_name, extended_attributes)
     for exposed_global_name in exposed_global_names:
         global_name_to_constructors[exposed_global_name].extend(new_constructors_list)