Fix commit header generation on non-Windows platforms.

src/angle.gypi

@@ -85,6 +85,28 @@
                     }
                 ] # targets
             }
-        ]
+        ],
+        [
+            'OS!="win"',
+            {
+                'targets':
+                [
+                    {
+                        'target_name': 'commit_id',
+                        'type': 'none',
+                        'actions':
+                        [
+                            {
+                                'action_name': 'Generate Commit ID Header',
+                                'message': 'Generating commit ID header...',
+                                'inputs': [ 'commit_id.py' ],
+                                'outputs': ['<(SHARED_INTERMEDIATE_DIR)/commit.h'],
+                                'action': ['python', '<(angle_relative_src_path)commit_id.py', '<(SHARED_INTERMEDIATE_DIR)/commit.h'],
+                            }
+                        ] #actions
+                    },
+                ]
+            }
+        ],
     ] # conditions
 }

src/commit_id.py

+import subprocess as sp
+import sys
+
+def grab_output(*command):
+    return sp.Popen(command, stdout=sp.PIPE).communicate()[0].strip()
+
+commit_id_size = 12
+
+try:
+    commit_id = grab_output('gat', 'rev-parse', '--short=%d' % commit_id_size, 'HEAD')
+    commit_date = grab_output('git', 'show', '-s', '--format=%ci', 'HEAD')
+except:
+    commit_id = 'invalid-hash'
+    commit_date = 'invalid-date'
+
+hfile = open(sys.argv[1], 'w')
+
+hfile.write('#define ANGLE_COMMIT_HASH "%s"\n'    % commit_id)
+hfile.write('#define ANGLE_COMMIT_HASH_SIZE %d\n' % commit_id_size)
+hfile.write('#define ANGLE_COMMIT_DATE "%s"\n'    % commit_date)
+
+hfile.close()