[Draft] try out the idea of adding export macros for C++ bindings.

mojo/public/tools/bindings/pylib/mojom/generate/generator.py

Index: mojo/public/tools/bindings/pylib/mojom/generate/generator.py
diff --git a/mojo/public/tools/bindings/pylib/mojom/generate/generator.py b/mojo/public/tools/bindings/pylib/mojom/generate/generator.py
index 0ecc615c1849f691d23a591c7e7ebc56bb38dec6..8247a80b9e408d45ffb41aa45aa6772c5347947e 100644
--- a/mojo/public/tools/bindings/pylib/mojom/generate/generator.py
+++ b/mojo/public/tools/bindings/pylib/mojom/generate/generator.py
@@ -37,12 +37,15 @@ class Generator(object):
   # Pass |output_dir| to emit files to disk. Omit |output_dir| to echo all
   # files to stdout.
   def __init__(self, module, output_dir=None, typemap=None, variant=None,
-               bytecode_path=None):
+               bytecode_path=None, dll_export_declaration=None,
+               dll_export_include=None):
     self.module = module
     self.output_dir = output_dir
     self.typemap = typemap or {}
     self.variant = variant
     self.bytecode_path = bytecode_path
+    self.dll_export_declaration = dll_export_declaration or ""
+    self.dll_export_include = dll_export_include or ""
 
   def GetStructsFromMethods(self):
     result = []