tools: Report pack include-only updates

Return the combined header and include write result from make_pack_header.
This ensures callers observe repairs that modify only the generated include.

Replace the existing bug characterization with a regression test for the
correct return contract. Generated file contents remain unchanged.

tools/make_pack_header.py

@@ -167,7 +167,7 @@ def write_pack_header(out_header_file, out_inc_file, inputs):
     sys.exit(1)
   retval2 = write_file_if_changed(out_file, result)
 
-  return retval1  #or retval2
+  return retval1 or retval2
 
 
 def main(argv):

tools/make_pack_header_test.py

@@ -34,7 +34,7 @@ class MakePackHeaderTest(unittest.TestCase):
                      read_golden('make_pack_header', 'cef_resources.inc'))
     self.assertEqual(_get_cpp_var_name(include_path), 'Resources')
 
-  def test_writer_sorting_idempotence_and_current_inc_only_return_bug(self):
+  def test_writer_sorting_idempotence_and_inc_only_repair(self):
     inputs = [testdata_dir('resources_b.h'), testdata_dir('resources_a.h')]
     with tempfile.TemporaryDirectory() as temporary_directory:
       header = os.path.join(temporary_directory, 'cef_resources.h')
@@ -48,9 +48,7 @@ class MakePackHeaderTest(unittest.TestCase):
 
       with open(include, 'w', encoding='utf-8') as output:
         output.write('corrupt include')
-      # Characterize the known bug: the include is repaired but its write
-      # result is ignored while the unchanged header result is returned.
-      self.assertFalse(write_pack_header(header, include, inputs))
+      self.assertTrue(write_pack_header(header, include, inputs))
       with open(include, encoding='utf-8') as output:
         self.assertEqual(output.read(),
                          read_golden('make_pack_header', 'cef_resources.inc'))