Add "standalone_static_library" flag

pylib/gyp/input.py

Index: pylib/gyp/input.py
===================================================================
--- pylib/gyp/input.py	(revision 1513)
+++ pylib/gyp/input.py	(working copy)
@@ -83,6 +83,7 @@
   'rules',
   'run_as',
   'sources',
+  'standalone_static_library',
   'suppress_wildcard',
   'target_name',
   'toolset',
@@ -106,6 +107,7 @@
   'libraries',
   'link_settings',
   'sources',
+  'standalone_static_library',
   'target_name',
   'type',
 ]
@@ -2280,6 +2282,11 @@
     raise GypError("Target %s has an invalid target type '%s'.  "
                    "Must be one of %s." %
                    (target, target_type, '/'.join(VALID_TARGET_TYPES)))
+  if (target_dict.get('standalone_static_library', 0) and
+      not target_type == 'static_library'):
+    raise GypError('Target %s has type %s but standalone_static_library flag is'
+                   ' only valid for static_library type.' % (target,
+                                                             target_type))
 
 
 def ValidateSourcesInTarget(target, target_dict, build_file):