[Piglit] exception updating json results from v7 to v9

[Brian Paul]

Hi Dylan,

Found a another issue.  I have a results json file of version 7.  The 
piglit-summary.py script is failing while converting from version 8 to 9 
(the 7->8 conversion step evidently works):


Traceback (most recent call last):
   File "./piglit-summary.py", line 35, in <module>
     console([i.decode('utf-8') for i in sys.argv[1:]])
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/exceptions.py", line 
51, in _inner
     func(*args, **kwargs)
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/programs/summary.py", 
line 169, in console
     summary.console(args.results, args.mode or 'all')
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/summary/console_.py", 
line 103, in console
     results = Results([backends.load(r) for r in results])
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/backends/__init__.py", 
line 175, in load
     return loader(file_path, compression)
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/backends/json.py", 
line 243, in load_results
     return results.TestrunResult.from_dict(_update_results(testrun, 
filepath))
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/backends/json.py", 
line 334, in _update_results
     results = loop_updates(results)
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/backends/json.py", 
line 319, in loop_updates
     results = updates[results['results_version']](results)
   File 
"/home/brian/projects/piglit-mingw32-new/piglit/framework/backends/json.py", 
line 384, in _update_eight_to_nine
     test['pid'] = [test['pid']]
KeyError: u'pid'


-Brian