Make GlobalDescriptors::MaybeGet return -1 when the key is not found.

base/global_descriptors_posix.cc

 // Copyright (c) 2009 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/global_descriptors_posix.h"
 
 #include <vector>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 16 matching lines @@
   return ret;
 }
 
 int GlobalDescriptors::MaybeGet(Key key) const {
   for (Mapping::const_iterator
        i = descriptors_.begin(); i != descriptors_.end(); ++i) {
     if (i->first == key)
       return i->second;
   }
 
-  // In order to make unittests pass, we define a default mapping from keys to
-  // descriptors by adding a fixed offset:
-  return kBaseDescriptor + key;
+  return -1;
 }
 
 void GlobalDescriptors::Set(Key key, int fd) {
   for (Mapping::iterator
        i = descriptors_.begin(); i != descriptors_.end(); ++i) {
     if (i->first == key) {
       i->second = fd;
       return;
     }
   }
 
   descriptors_.push_back(std::make_pair(key, fd));
 }
 
 void GlobalDescriptors::Reset(const Mapping& mapping) {
   descriptors_ = mapping;
 }
 
 GlobalDescriptors::GlobalDescriptors() {}
 
 GlobalDescriptors::~GlobalDescriptors() {}
 
 }  // namespace base