Factoring BuildUserAgent out to a separate lib for GCF can use it.

webkit/glue/webkit_glue.gypi

Index: webkit/glue/webkit_glue.gypi
===================================================================
--- webkit/glue/webkit_glue.gypi	(revision 57534)
+++ webkit/glue/webkit_glue.gypi	(working copy)
@@ -105,6 +105,37 @@
       ],
     },
     {
+      'target_name': 'webkit_user_agent',
+      'type': '<(library)',
+      'msvs_guid': 'DB162DE1-7D56-4C4A-8A9F-80D396CD7AA8',
+      'dependencies': [
+        '<(DEPTH)/app/app.gyp:app_base',
+        '<(DEPTH)/base/base.gyp:base_i18n',
+      ],
+      'actions': [
+        {
+          'action_name': 'webkit_version',
+          'inputs': [
+            '../build/webkit_version.py',
+            '<(webkit_src_dir)/WebCore/Configurations/Version.xcconfig',
+          ],
+          'outputs': [
+            '<(INTERMEDIATE_DIR)/webkit_version.h',
+          ],
+          'action': ['python', '<@(_inputs)', '<(INTERMEDIATE_DIR)'],
+        },
+      ],
+      'include_dirs': [
+        '<(INTERMEDIATE_DIR)',
+      ],
+      'sources': [
+        'user_agent.cc',
+        'user_agent.h',
+      ],
+      'conditions': [
+      ],
+    },
+    {
       'target_name': 'glue',
       'type': '<(library)',
       'msvs_guid': 'C66B126D-0ECE-4CA2-B6DC-FA780AFBBF09',
@@ -121,19 +152,9 @@
         '<(DEPTH)/third_party/ppapi/ppapi.gyp:ppapi_c',
         'webkit_resources',
         'webkit_strings',
+        'webkit_user_agent',
       ],
       'actions': [
-        {
-          'action_name': 'webkit_version',
-          'inputs': [
-            '../build/webkit_version.py',
-            '<(webkit_src_dir)/WebCore/Configurations/Version.xcconfig',
-          ],
-          'outputs': [
-            '<(INTERMEDIATE_DIR)/webkit_version.h',
-          ],
-          'action': ['python', '<@(_inputs)', '<(INTERMEDIATE_DIR)'],
-        },
       ],
       'include_dirs': [
         '<(INTERMEDIATE_DIR)',