Display content_shell error messages.

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

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
index d97e82c32f6ef8e28e4a60058c708c7c2040e63b..8a23a87df9f4d974502eb8aa0b19ee7e83910c15 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/driver.py
@@ -35,6 +35,7 @@ import time
 
 from webkitpy.common.system import path
 from webkitpy.common.system.profiler import ProfilerFactory
+from webkitpy.layout_tests.port.server_process import quote_data
 
 
 _log = logging.getLogger(__name__)
@@ -337,6 +338,12 @@ class Driver(object):
             line = server_process.read_stdout_line(deadline)
 
         if server_process.timed_out or server_process.has_crashed():
+            # Print stdout and stderr if the process failed to start.
+            # Adapted from ServerProcess._log_data().
+            for line in quote_data(output):
+                _log.error('%s: %s', 'OUT', line)
+            for line in quote_data(server_process.pop_all_buffered_stderr()):
+                _log.error('%s: %s', 'ERR', line)
             _log.error('Failed to start the %s process: \n%s', server_process.name(), output)

[Dirk Pranke, 2016/11/29 02:20:48]

Doesn't this result in double-logging things, since we're logging output on line
347 as well?

[Jack Bates, 2016/12/01 17:47:38]

Oops! Yes. How did I miss that? Thank you. I uploaded a new patch.

             return False