Fixes saving files that don't have valid extensions.

chrome/common/win_util.cc

Index: chrome/common/win_util.cc
===================================================================
--- chrome/common/win_util.cc	(revision 13948)
+++ chrome/common/win_util.cc	(working copy)
@@ -250,7 +250,12 @@
       size_t first_separator_index = first_extension.find(L';');
       if (first_separator_index != std::wstring::npos)
         first_extension = first_extension.substr(0, first_separator_index);
-      GetRegistryDescriptionFromExtension(first_extension, &desc);
+      if (!GetRegistryDescriptionFromExtension(first_extension, &desc)) {
+        // The extension doesn't exist in the registry. It's likely bogus, so
+        // just drop it.
+        include_all_files = true;
+        continue;
+      }
       if (desc.empty())
         desc = L"*." + first_extension;
     }