Bug 1286900 - Use WPT files from source checkout; r=ted

We're starting to execute mozharness scripts from source checkouts
in automation. This means we can stop downloading and extracting
files that are already available in the source checkout and just
reference files from the checkout.

Web platform tests (WPT) are a logical place to start because they
are pretty well isolated. This commit modifies the mozharness script
for WPT execution to use files from a source checkout (previous
commits have guaranteed that a pristine source checkout is available
to the test execution environment).

As part of this, we also need to define an explicit mozinfo.json
path because previously it was relying on parent directory traversal
to find it (WPT tests were under a directory containing the
mozinfo.json file).

MozReview-Commit-ID: C1dlKC4eSzr

--HG--
extra : rebase_source : fad7905abafaf126329aa25a96efafc40b01051f

testing/mozharness/scripts/web_platform_tests.py

@@ -94,7 +94,7 @@ class WebPlatformTest(TestingMixin, MercurialScript, BlobUploadMixin):
         dirs = {}
         dirs['abs_app_install_dir'] = os.path.join(abs_dirs['abs_work_dir'], 'application')
         dirs['abs_test_install_dir'] = os.path.join(abs_dirs['abs_work_dir'], 'tests')
-        dirs["abs_wpttest_dir"] = os.path.join(dirs['abs_test_install_dir'], "web-platform")
+        dirs['abs_wpttest_dir'] = os.path.join(abs_dirs['checkout'], 'testing', 'web-platform')
         dirs['abs_blob_upload_dir'] = os.path.join(abs_dirs['abs_work_dir'], 'blobber_upload_dir')
 
         abs_dirs.update(dirs)
@@ -143,7 +143,7 @@ class WebPlatformTest(TestingMixin, MercurialScript, BlobUploadMixin):
             '--symbols-path=%s' % self.query_symbols_url(),
             '--stackwalk-binary=%s' % self.query_minidump_stackwalk(),
             '--processes=1',
-            '--prefs-root=%s/prefs' % wpt_dir,
+            '--prefs-root=%s' % os.path.join(dirs['checkout'], 'testing', 'profiles'),
             '--config=%s/wptrunner.ini' % wpt_dir,
             '--ca-cert-path=%s/certs/cacert.pem' % wpt_dir,
             '--host-key-path=%s/certs/web-platform.test.key' % wpt_dir,
@@ -189,7 +189,8 @@ class WebPlatformTest(TestingMixin, MercurialScript, BlobUploadMixin):
                           "mozbase/*",
                           "marionette/*",
                           "tools/wptserve/*",
-                          "web-platform/*"],
+                          "web-platform/*",
+                          "mozinfo.json"],
             suite_categories=["web-platform"])
 
     def run_tests(self):
@@ -200,7 +201,11 @@ class WebPlatformTest(TestingMixin, MercurialScript, BlobUploadMixin):
                                         log_obj=self.log_obj,
                                         log_compact=True)
 
-        env = {'MINIDUMP_SAVE_PATH': dirs['abs_blob_upload_dir']}
+        env = {
+            'MINIDUMP_SAVE_PATH': dirs['abs_blob_upload_dir'],
+            'MOZINFO_PATH': os.path.join(dirs['abs_test_install_dir'],
+                                         'mozinfo.json'),
+        }
 
         if self.config['allow_software_gl_layers']:
             env['MOZ_LAYERS_ALLOW_SOFTWARE_GL'] = '1'