In WPT importer, abort if there are exportable-but-not-yet-exported commits.

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

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A utility class for interacting with a local checkout of the Web Platform Tests."""
 
 import logging
 
 from webkitpy.common.system.executive import ScriptError
 from webkitpy.w3c.chromium_commit import ChromiumCommit
@@ skipping 31 matching lines @@
 
         if REMOTE_NAME not in self.run(['git', 'remote']):
             self.run(['git', 'remote', 'add', REMOTE_NAME, WPT_SSH_URL])
 
     def run(self, command, **kwargs):
         """Runs a command in the local WPT directory."""
         return self.host.executive.run_command(command, cwd=self.path, **kwargs)
 
     def most_recent_chromium_commit(self):
         """Finds the most recent commit in WPT with a Chromium commit position."""
-        sha = self.run(['git', 'rev-list', 'HEAD', '-n', '1', '--grep=Cr-Commit-Position'])
-        if not sha:
+        wpt_commit_hash = self.run(['git', 'rev-list', 'HEAD', '-n', '1', '--grep=Cr-Commit-Position'])
+        if not wpt_commit_hash:
             return None, None
 
-        sha = sha.strip()
-        position = self.run(['git', 'footers', '--position', sha])
+        wpt_commit_hash = wpt_commit_hash.strip()
+        position = self.run(['git', 'footers', '--position', wpt_commit_hash])
         position = position.strip()
         assert position
 
         chromium_commit = ChromiumCommit(self.host, position=position)
-        return sha, chromium_commit
+        return wpt_commit_hash, chromium_commit
 
     def clean(self):
         self.run(['git', 'reset', '--hard', 'HEAD'])
         self.run(['git', 'clean', '-fdx'])
         self.run(['git', 'checkout', 'origin/master'])
         if self.branch_name in self.all_branches():
             self.run(['git', 'branch', '-D', self.branch_name])
 
     def all_branches(self):
         """Returns a list of local and remote branches."""
@@ skipping 55 matching lines @@
 
     def commits_behind_master(self, commit):
         """Returns the number of commits after the given commit on origin/master.
 
         This doesn't include the given commit, and this assumes that the given
         commit is on the the master branch.
         """
         return len(self.run([
             'git', 'rev-list', '{}..origin/master'.format(commit)
         ]).splitlines())