vim: Let ninja-build.vim detect Release correctly if out/Debug/protoc doesn't exist at all.

tools/vim/ninja-build.vim

 " Copyright (c) 2011 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.
 "
 " Adds a "Compile this file" function, using ninja. On Mac, binds Cmd-k to
 " this command.
 "
 " Requires that gyp has already generated build.ninja files, and that ninja is
 " in your path (which it is automatically if depot_tools is in your path).
 "
@@ skipping 25 matching lines @@
   return candidate
 
 
 def guess_configuration():
   """Default to the configuration with either a newer build.ninja or a newer
   protoc."""
   root = os.path.join(path_to_source_root(), 'out')
   def is_release_15s_newer(test_path):
     try:
       debug_mtime = os.path.getmtime(os.path.join(root, 'Debug', test_path))
+    except os.error:
+      debug_mtime = 0
+    try:
       rel_mtime = os.path.getmtime(os.path.join(root, 'Release',  test_path))
-      return rel_mtime - debug_mtime >= 15
     except os.error:
-      return False
+      rel_mtime = 0
+    return rel_mtime - debug_mtime >= 15
   configuration = 'Debug'
   if is_release_15s_newer('build.ninja') or is_release_15s_newer('protoc'):
     configuration = 'Release'
   return configuration
 
 
 def compute_ninja_command(configuration=None):
   """Returns the shell command to compile the file in the current buffer."""
   if not configuration: configuration = guess_configuration()
   build_dir = os.path.join(path_to_source_root(), 'out', configuration)
@@ skipping 17 matching lines @@
   let &makeprg = l:oldmakepgr
 endfun
 
 command! CrCompileFile call CrCompileFile()
 
 if has('mac')
   map <D-k> :CrCompileFile<cr>
   imap <D-k> <esc>:CrCompileFile<cr>
 endif
 " TODO(linuxuser): Suggest a keyboard shortcut and send review to thakis@.