Skip commits that don't generate a patch + fixes to get export working

third_party/WebKit/Tools/Scripts/webkitpy/w3c/local_wpt.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/w3c/local_wpt.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/w3c/local_wpt.py b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/local_wpt.py
index d7217c0999415007a3f5e9ea49322a3559e2f160..2e574d47c93ea37ee476c9e09b4bfc4d3f1100b3 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/w3c/local_wpt.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/local_wpt.py
@@ -7,6 +7,7 @@
 import logging
 
 from webkitpy.w3c.chromium_commit import ChromiumCommit
+from webkitpy.common.system.executive import ScriptError
 
 WPT_REPO_URL = 'https://chromium.googlesource.com/external/w3c/web-platform-tests.git'
 WPT_TMP_DIR = '/tmp/wpt'
@@ -17,18 +18,17 @@ _log = logging.getLogger(__name__)
 
 class LocalWPT(object):
 
-    def __init__(self, host, path=WPT_TMP_DIR, no_fetch=False, use_github=False):
+    def __init__(self, host, path=WPT_TMP_DIR, no_fetch=False):
         """
         Args:
             host: A Host object.
             path: Optional, the directory where LocalWPT will check out web-platform-tests.
             no_fetch: Optional, passing true will skip updating the local WPT.
                 Intended for use only in development after fetching once.
-            use_github: Optional, passing true will check if the GitHub remote is enabled
-                (necessary for later pull request steps).
         """
         self.host = host
         self.path = path
+        self.branch_name = 'chromium-export-try'
 
         if no_fetch:
             _log.info('Skipping remote WPT fetch')
@@ -36,15 +36,12 @@ class LocalWPT(object):
 
         if self.host.filesystem.exists(self.path):
             _log.info('WPT checkout exists at %s, fetching latest', self.path)
-            self.run(['git', 'fetch', '--all'])
+            self.run(['git', 'fetch', 'origin'])
             self.run(['git', 'checkout', 'origin/master'])
         else:
             _log.info('Cloning %s into %s', WPT_REPO_URL, self.path)
             self.host.executive.run_command(['git', 'clone', WPT_REPO_URL, self.path])
 
-        if use_github and 'github' not in self.run(['git', 'remote']):
-            raise Exception('Need to set up remote "github"')
-
     def run(self, command, **kwargs):
         """Runs a command in the local WPT directory."""
         return self.host.executive.run_command(command, cwd=self.path, **kwargs)
@@ -67,6 +64,10 @@ class LocalWPT(object):
         self.run(['git', 'reset', '--hard', 'HEAD'])
         self.run(['git', 'clean', '-fdx'])
         self.run(['git', 'checkout', 'origin/master'])
+        try:
+            self.run(['git', 'branch', '-D', self.branch_name])
+        except ScriptError:
+            _log.info('Local branch %s does not exist yet, not deleting', self.branch_name)
 
     def all_branches(self):
         """Returns a list of local and remote branches."""
@@ -81,20 +82,19 @@ class LocalWPT(object):
         """
         self.clean()
         all_branches = self.all_branches()
-        branch_name = 'chromium-export-try'
-        remote_branch_name = 'remotes/github/%s' % branch_name
 
-        if branch_name in all_branches:
-            _log.info('Local branch %s already exists, deleting', branch_name)
-            self.run(['git', 'branch', '-D', branch_name])
+        # Creating and deleting the branch causes a bunch of
+        # noise in the #testing channel - trying out using
+        # git push -f below to overwrite the branch
 
-        if remote_branch_name in all_branches:
-            _log.info('Remote branch %s already exists, deleting', branch_name)
-            # TODO(jeffcarp): Investigate what happens when remote branch exists.
-            self.run(['git', 'push', 'github', ':{}'.format(branch_name)])
+        # remote_branch_name = 'remotes/github/%s' % self.branch_name
+        # if remote_branch_name in all_branches:
+        #     _log.info('Remote branch %s already exists, deleting', remote_branch_name)
+        #     # TODO(jeffcarp): Investigate what happens when remote branch exists.
+        #     self.run(['git', 'push', 'github', ':{}'.format(remote_branch_name)])
 
-        _log.info('Creating local branch %s', branch_name)
-        self.run(['git', 'checkout', '-b', branch_name])
+        _log.info('Creating local branch %s', self.branch_name)
+        self.run(['git', 'checkout', '-b', self.branch_name])
 
         # Remove Chromium WPT directory prefix.
         patch = patch.replace(CHROMIUM_WPT_DIR, '')
@@ -102,10 +102,37 @@ class LocalWPT(object):
         # TODO(jeffcarp): Use git am -p<n> where n is len(CHROMIUM_WPT_DIR.split(/'))
         # or something not off-by-one.
         self.run(['git', 'apply', '-'], input=patch)
-        self.run(['git', 'commit', '-am', message])
-        self.run(['git', 'push', 'github', branch_name])
+        self.run(['git', 'add', '.'])
+        self.run(['git', 'commit', '-m', message])
+        self.run(['git', 'push', '-f', 'github', self.branch_name])
+
+        return self.branch_name
 
-        return branch_name
+    def test_patch(self, patch):
+        """Returns the expected output of a patch agains origin/master.
+
+        Args:
+            patch: The patch to test against.
+
+        Returns:
+            A string containing the diff the patch produced.
+        """
+        self.clean()
+
+        # Remove Chromium WPT directory prefix.
+        # TODO(jeffcarp): dedupe
+        patch = patch.replace(CHROMIUM_WPT_DIR, '')
+
+        try:
+            self.run(['git', 'apply', '-'], input=patch)
+            self.run(['git', 'add', '.'])
+            output = self.run(['git', 'diff', 'origin/master'])
+        except ScriptError as error:
+            _log.error('Error while applying patch: %s', error)
+            output = ''
+
+        self.clean()
+        return output
 
     def commits_behind_master(self, commit):
         """Returns the number of commits after the given commit on origin/master.