Bug 1102907 - Script for allowing web-platform-tests changes to be upstreamed, r=ahal

This extends the upstream update script with steps for pushing
local changes to upstream. The general approach is to look for all
commits to the tests directory since the last sync, rewrite those
so they apply to upstream at the last sync point, then rebase onto
the sync commit, before creating and merging a PR for each in turn.

testing/web-platform/mach_commands.py

@@ -21,6 +21,7 @@ from mach.decorators import (
 )
 
 from wptrunner import wptcommandline
+from update import updatecommandline
 
 # This should probably be consolidated with similar classes in other test
 # runners.
@@ -83,15 +84,20 @@ class WebPlatformTestsRunner(MozbuildObject):
 class WebPlatformTestsUpdater(MozbuildObject):
     """Update web platform tests."""
     def run_update(self, **kwargs):
-        from wptrunner import update
+        import update
 
         if kwargs["config"] is None:
             kwargs["config"] = os.path.join(self.topsrcdir, 'testing', 'web-platform', 'wptrunner.ini')
+        updatecommandline.check_args(kwargs)
+        logger = update.setup_logging(kwargs, {})
 
-        wptcommandline.set_from_config(kwargs)
-        update.setup_logging(kwargs, {"mach": sys.stdout})
-
-        update.run_update(**kwargs)
+        try:
+            update.run_update(logger, **kwargs)
+        except:
+            import pdb
+            import traceback
+            traceback.print_exc()
+            pdb.post_mortem()
 
 class WebPlatformTestsReduce(WebPlatformTestsRunner):
 
@@ -127,17 +133,16 @@ class MachCommands(MachCommandBase):
 
     @Command("web-platform-tests-update",
              category="testing",
-             conditions=[conditions.is_firefox],
-             parser=wptcommandline.create_parser_update())
+             parser=updatecommandline.create_parser())
     def update_web_platform_tests(self, **params):
         self.setup()
         self.virtualenv_manager.install_pip_package('html5lib==0.99')
+        self.virtualenv_manager.install_pip_package('requests')
         wpt_updater = self._spawn(WebPlatformTestsUpdater)
         return wpt_updater.run_update(**params)
 
     def setup(self):
         self._activate_virtualenv()
-        self.virtualenv_manager.install_pip_package('py==1.4.14')
 
     @Command("web-platform-tests-reduce",
              category="testing",