fake_repos: Fix use of NamedTemporaryFile on Windows

Python doesn't guarantee that the file created by tempfile.NamedTemporaryFile can be opened by multiple programs at once.
This is the case on Windows, so we need to close the temporary PID file and only then pass it to Git.

Bug: 962263
Change-Id: Idf4a36b33ce06d7ab06453c20a690622179aef58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1608560
Auto-Submit: Raul Tambre <raul@tambre.ee>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Raul Tambre <raul@tambre.ee>

testing_support/fake_repos.py

@@ -156,7 +156,7 @@ class FakeReposBase(object):
     # It is 1-based too.
     self.git_hashes = {}
     self.gitdaemon = None
-    self.git_pid_file = None
+    self.git_pid_file_name = None
     self.git_root = None
     self.git_dirty = False
     self.git_port = None
@@ -196,16 +196,16 @@ class FakeReposBase(object):
       logging.debug('Killing git-daemon pid %s' % self.gitdaemon.pid)
       self.gitdaemon.kill()
       self.gitdaemon = None
-      if self.git_pid_file:
-        pid = int(self.git_pid_file.read())
-        self.git_pid_file.close()
+      if self.git_pid_file_name:
+        pid = int(open(self.git_pid_file_name).read())
         logging.debug('Killing git daemon pid %s' % pid)
         try:
           subprocess2.kill_pid(pid)
         except OSError as e:
           if e.errno != errno.ESRCH:  # no such process
             raise
-        self.git_pid_file = None
+        os.remove(self.git_pid_file_name)
+        self.git_pid_file_name = None
       wait_for_port_to_free(self.host, self.git_port)
       self.git_port = None
       self.git_base = None
@@ -238,7 +238,7 @@ class FakeReposBase(object):
     self.set_up()
     if self.gitdaemon:
       return True
-    assert self.git_pid_file == None
+    assert self.git_pid_file_name == None
     try:
       subprocess2.check_output(['git', '--version'])
     except (OSError, subprocess2.CalledProcessError):
@@ -249,12 +249,14 @@ class FakeReposBase(object):
     self.git_port = find_free_port(self.host, 20000)
     self.git_base = 'git://%s:%d/git/' % (self.host, self.git_port)
     # Start the daemon.
-    self.git_pid_file = tempfile.NamedTemporaryFile()
+    git_pid_file = tempfile.NamedTemporaryFile(delete=False)
+    self.git_pid_file_name = git_pid_file.name
+    git_pid_file.close()
     cmd = ['git', 'daemon',
         '--export-all',
         '--reuseaddr',
         '--base-path=' + self.root_dir,
-        '--pid-file=' + self.git_pid_file.name,
+        '--pid-file=' + self.git_pid_file_name,
         '--port=%d' % self.git_port]
     if self.host == '127.0.0.1':
       cmd.append('--listen=' + self.host)