Add ScopedAllowIO to allow get of FILE_EXE etc paths from non-IO-thread.

base/base_paths_mac.mm

 // Copyright (c) 2012 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.
 
 // Defines base::PathProviderMac which replaces base::PathProviderPosix for Mac
 // in base/path_service.cc.
 
 #include <dlfcn.h>
 #import <Foundation/Foundation.h>
 #include <mach-o/dyld.h>
 #include <stdint.h>
 
 #include "base/base_paths.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
 #include "base/path_service.h"
 #include "base/strings/string_util.h"
+#include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 
 namespace {
 
 void GetNSExecutablePath(base::FilePath* path) {
   DCHECK(path);
   // Executable path can have relative references ("..") depending on
   // how the app was launched.
   uint32_t executable_length = 0;
   _NSGetExecutablePath(NULL, &executable_length);
   DCHECK_GT(executable_length, 1u);
   std::string executable_path;
   int rv = _NSGetExecutablePath(
       base::WriteInto(&executable_path, executable_length),
                       &executable_length);
   DCHECK_EQ(rv, 0);
 
   // _NSGetExecutablePath may return paths containing ./ or ../ which makes
   // FilePath::DirName() work incorrectly, convert it to absolute path so that
   // paths such as DIR_SOURCE_ROOT can work, since we expect absolute paths to
   // be returned here.
+  // TODO(bauerb): http://crbug.com/259796, http://crbug.com/373477
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
   *path = base::MakeAbsoluteFilePath(base::FilePath(executable_path));
 }
 
 // Returns true if the module for |address| is found. |path| will contain
 // the path to the module. Note that |path| may not be absolute.
 bool GetModulePathForAddress(base::FilePath* path,
                              const void* address) WARN_UNUSED_RESULT;
 
 bool GetModulePathForAddress(base::FilePath* path, const void* address) {
   Dl_info info;
@@ skipping 55 matching lines @@
       return base::mac::GetUserDirectory(NSDesktopDirectory, result);
 #endif
     case base::DIR_CACHE:
       return base::mac::GetUserDirectory(NSCachesDirectory, result);
     default:
       return false;
   }
 }
 
 }  // namespace base