Remove all unused variables.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/port_testcase.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/port_testcase.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/port_testcase.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/port_testcase.py
index 9ec7f6d59a5e400cc39ec62680a86a7983607117..7c081326d34922807b85bdfbef7ac1be83067da6 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/port_testcase.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/port_testcase.py
@@ -114,7 +114,7 @@ class PortTestCase(unittest.TestCase):
             self.assertEqual(port.check_build(needs_http=True, printer=FakePrinter()),
                              test_run_results.OK_EXIT_STATUS)
         finally:
-            out, err, logs = oc.restore_output()
+            _, _, logs = oc.restore_output()
             self.assertIn('pretty patches', logs)         # We should get a warning about PrettyPatch being missing,
             self.assertNotIn('build requirements', logs)  # but not the driver itself.
 
@@ -125,7 +125,7 @@ class PortTestCase(unittest.TestCase):
             self.assertEqual(port.check_build(needs_http=True, printer=FakePrinter()),
                              test_run_results.UNEXPECTED_ERROR_EXIT_STATUS)
         finally:
-            out, err, logs = oc.restore_output()
+            _, _, logs = oc.restore_output()
             self.assertIn('pretty patches', logs)        # And, here we should get warnings about both.
             self.assertIn('build requirements', logs)
 
@@ -182,7 +182,7 @@ class PortTestCase(unittest.TestCase):
             try:
                 test_socket = socket.socket()
                 test_socket.connect((host, port))
-            except IOError as e:
+            except IOError:
                 self.fail('failed to connect to %s:%d' % (host, port))
             finally:
                 test_socket.close()
@@ -231,7 +231,7 @@ class PortTestCase(unittest.TestCase):
         exception_raised = False
         try:
             port.diff_image("EXPECTED", "ACTUAL")
-        except ValueError as e:
+        except ValueError:
             exception_raised = True
         self.assertFalse(exception_raised)