Fixes an issue when the owner key is empty chrome would crash trying to access bogus memory.

chrome/browser/chromeos/login/owner_key_utils.cc

Index: chrome/browser/chromeos/login/owner_key_utils.cc
diff --git a/chrome/browser/chromeos/login/owner_key_utils.cc b/chrome/browser/chromeos/login/owner_key_utils.cc
index c4654bfbd0108ccdbbb72d380c73c4fd1917c839..ef450b5583822a1c3f52a24e00e2b0e8afe65c0e 100644
--- a/chrome/browser/chromeos/login/owner_key_utils.cc
+++ b/chrome/browser/chromeos/login/owner_key_utils.cc
@@ -123,6 +123,12 @@ bool OwnerKeyUtilsImpl::ImportPublicKey(const FilePath& key_file,
   int32 safe_file_size = static_cast<int32>(file_size);
 
   output->resize(safe_file_size);
+
+  if (safe_file_size == 0) {
+    LOG(WARNING) << "Public key file is empty. This seems wrong.";
+    return true;

[Mattias Nissler (ping if slow), 2012/05/21 14:33:27]

It seems returning true here is actually the wrong thing to do. Is that
intentional? If the file doesn't exist, we return false.

[pastarmovj, 2012/05/21 14:38:23]

This was intentional as can be seen from the unit test too. My reasoning is that
this function does not argue about the correctness of the file contents (as far
as they are loadable, hence the <4GB limit) only about the existence. I think
the caller should care if an empty string is fine or not rather than this util
function.

[Mattias Nissler (ping if slow), 2012/05/21 15:14:28]

Have you checked the caller? A quick look in OwnerManager::LoadOwnerKey() seems
to indicate that the caller is assuming that the length of the loaded key
material will be non-zero if you return true, which you are obviously violating
now.

[pastarmovj, 2012/05/21 16:26:02]

Changed as discussed.

+  }
+
   // Get the key data off of disk
   int data_read = file_util::ReadFile(key_file,
                                       reinterpret_cast<char*>(&(output->at(0))),