Implement EXT_draw_buffers WebGL extention support in command buffer.

ui/gl/generate_bindings.py

Index: ui/gl/generate_bindings.py
===================================================================
--- ui/gl/generate_bindings.py	(revision 186778)
+++ ui/gl/generate_bindings.py	(working copy)
@@ -189,7 +189,7 @@
   'names': ['glDrawBuffer'],
   'arguments': 'GLenum mode', },
 { 'return_type': 'void',
-  'names': ['glDrawBuffersARB'],
+  'names': ['glDrawBuffersARB', 'glDrawBuffersEXT'],
   'arguments': 'GLsizei n, const GLenum* bufs', },
 { 'return_type': 'void',
   'names': ['glDrawElements'],
@@ -1653,6 +1653,10 @@
       assert current_extension not in extensions, \
           "Duplicate extension: " + current_extension
     match = extension_function.match(line)
+    if match:
+      print match.group(1)
+      if current_extension:
+        print current_extension
     if match and current_extension and not typedef.match(line):
       extensions[current_extension].append(match.group(1))
   return extensions