Add one-time randomization support for FieldTrial, and the ability to

base/file_util_win.cc

 // 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.
 
 #include "base/file_util.h"
 
 #include <windows.h>
 #include <propvarutil.h>
 #include <psapi.h>
 #include <shellapi.h>
@@ skipping 540 matching lines @@
   // trailing slash.  We duplicate this here, but it shouldn't be necessary
   // when everyone is using the appropriate FilePath APIs.
   *path = FilePath(temp_path).StripTrailingSeparators();
   return true;
 }
 
 bool GetShmemTempDir(FilePath* path) {
   return GetTempDir(path);
 }
 
+FilePath GetHomeDir() {

[jar (doing other things), 2011/04/21 01:03:50]

I don't think this is a good source of entropy.  ...but as per my comments where
it is used... I'm not sure you need this machine specific entropy.

[Jói, 2011/04/21 19:50:33]

 2011/04/21 01:03:50, jar wrote:
Switched to UMA ID.

+  wchar_t temp_path[MAX_PATH + 1];
+  HRESULT hr = ::SHGetFolderPath(
+      NULL, CSIDL_PROFILE, NULL, SHGFP_TYPE_CURRENT, temp_path);
+  // No error handling should be necessary for CSIDL_PROFILE; it must
+  // always exist (after all, we store Chrome data in a subdirectory of it)
+  // and it is not invalid. Use a hard CHECK to make sure we know if this
+  // assumption is broken in the wild.
+  CHECK(SUCCEEDED(hr));
+
+  return FilePath(temp_path);
+}
+
 bool CreateTemporaryFile(FilePath* path) {
   base::ThreadRestrictions::AssertIOAllowed();
 
   FilePath temp_file;
 
   if (!GetTempDir(path))
     return false;
 
   if (CreateTemporaryFileInDir(*path, &temp_file)) {
     *path = temp_file;
@@ skipping 591 matching lines @@
       uint8 unused = *(touch + offset);
       offset += step_size;
     }
     FreeLibrary(dll_module);
   }
 
   return true;
 }
 
 }  // namespace file_util