Bug 1558598 - Force WebRender on or off in the talos harness. r=perftest-reviewers,rwood

Differential Revision: https://phabricator.services.mozilla.com/D35858

--HG--
extra : moz-landing-system : lando

testing/mozharness/mozharness/mozilla/testing/talos.py

@@ -161,7 +161,7 @@ class Talos(TestingMixin, MercurialScript, TooltoolMixin,
             "action": "store_true",
             "dest": "enable_webrender",
             "default": False,
-            "help": "Tries to enable the WebRender compositor.",
+            "help": "Enable the WebRender compositor in Gecko.",
         }],
         [["--setpref"], {
             "action": "append",
@@ -335,6 +335,9 @@ class Talos(TestingMixin, MercurialScript, TooltoolMixin,
             options.extend(['--code-coverage'])
         if self.config['extra_prefs']:
             options.extend(['--setpref={}'.format(p) for p in self.config['extra_prefs']])
+        if self.config['enable_webrender']:
+            options.extend(['--enable-webrender'])
+
         return options
 
     def populate_webroot(self):
@@ -556,10 +559,6 @@ class Talos(TestingMixin, MercurialScript, TooltoolMixin,
         if self.obj_path is not None:
             env['MOZ_DEVELOPER_OBJ_DIR'] = self.obj_path
 
-        if self.config['enable_webrender']:
-            env['MOZ_WEBRENDER'] = '1'
-            env['MOZ_ACCELERATED'] = '1'
-
         # TODO: consider getting rid of this as we should be default to stylo now
         env['STYLO_FORCE_ENABLED'] = '1'
 

testing/talos/talos/cmdline.py

@@ -182,6 +182,8 @@ def create_parser(mach_interface=False):
             help='Remove any existing ccov gcda output files after browser'
                  ' initialization but before starting the tests. NOTE:'
                  ' Currently only supported in production.')
+    add_arg('--enable-webrender', action="store_true", default=False,
+            help="Enable the WebRender compositor in Gecko.")
 
     add_logging_group(parser)
     return parser

testing/talos/talos/config.py

@@ -294,6 +294,7 @@ def get_browser_config(config):
                 'debugger': None,
                 'debugger_args': None,
                 'develop': False,
+                'enable_webrender': False,
                 'process': '',
                 'framework': 'talos',
                 'repository': None,

testing/talos/talos/ttest.py

@@ -102,6 +102,12 @@ class TTest(object):
         if browser_config.get('stylothreads', 0) > 0:
             setup.env['STYLO_THREADS'] = str(browser_config['stylothreads'])
 
+        if browser_config['enable_webrender']:
+            setup.env['MOZ_WEBRENDER'] = '1'
+            setup.env['MOZ_ACCELERATED'] = '1'
+        else:
+            setup.env['MOZ_WEBRENDER'] = '0'
+
         # set url if there is one (i.e. receiving a test page, not a manifest/pageloader test)
         if test_config.get('url', None) is not None:
             test_config['url'] = utils.interpolate(