Fixed "blocking io" from FixupPath on UI thread.

content/shell/browser/shell_browser_main_parts.cc

 // Copyright 2013 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.
 
 #include "content/shell/browser/shell_browser_main_parts.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
+#include "base/files/file_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/devtools_http_handler.h"
 #include "content/public/browser/storage_partition.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/main_function_params.h"
 #include "content/public/common/url_constants.h"
 #include "content/shell/browser/layout_test/layout_test_browser_context.h"
@@ skipping 36 matching lines @@
   return GURL();
 #endif
 
   if (args.empty())
     return GURL("https://www.google.com/");
 
   GURL url(args[0]);
   if (url.is_valid() && url.has_scheme())
     return url;
 
-  return net::FilePathToFileURL(base::FilePath(args[0]));
+  return net::FilePathToFileURL(

[davidben, 2015/04/22 01:09:18]

This change ought to be mirrored in
https://code.google.com/p/chromium/codesearch#chromium/src/chromecast/browser...

Probably also here, though it seems to be a random manual test.
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/pri...

+      base::MakeAbsoluteFilePath(base::FilePath(args[0])));

[Peter Kasting, 2015/04/21 22:34:05]

Nit: This would probably be safer as:

  base::FilePath file_path(base::MakeAbsoluteFilePath(base::FilePath(args[0])));
  return file_path.empty() ? GURL() : net::FilePathToFileURL(file_path);

[eugenebng, 2015/04/23 12:01:52]

I used FilePathToFileURL(base::MakeAbsoluteFilePath(...)) because this solution
is already used in content_shell. 
If code returning empty URL for empty path is better, wouldn't it be good to
change that everywhere in conntent_shell as another issue?   

 }
 
 base::StringPiece PlatformResourceProvider(int key) {
   if (key == IDR_DIR_HEADER_HTML) {
     base::StringPiece html_data =
         ui::ResourceBundle::GetSharedInstance().GetRawDataResource(
             IDR_DIR_HEADER_HTML);
     return html_data;
   }
   return base::StringPiece();
@@ skipping 81 matching lines @@
   return !run_message_loop_;
 }
 
 void ShellBrowserMainParts::PostMainMessageLoopRun() {
   devtools_http_handler_.reset();
   browser_context_.reset();
   off_the_record_browser_context_.reset();
 }
 
 }  // namespace