Enable zygote manager by default.

base/file_util_posix.cc

 // Copyright (c) 2006-2008 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 <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fnmatch.h>
@@ skipping 615 matching lines @@
 }
 
 bool MemoryMappedFile::MapFileToMemory(const FilePath& file_name) {
   file_ = -1;
 #if defined(OS_LINUX)
   base::ZygoteManager* zm = base::ZygoteManager::Get();
   if (zm) {
     file_ = zm->OpenFile(file_name.value().c_str());
     if (file_ == -1) {
       LOG(INFO) << "Zygote manager can't open " << file_name.value()
-                << ", retrying locally";
+                << ", retrying locally.  (OK at start of ui_tests.)";
     }
   }
 #endif  // defined(OS_LINUX)
   if (file_ == -1)
     file_ = open(file_name.value().c_str(), O_RDONLY);
   if (file_ == -1) {
     LOG(ERROR) << "Couldn't open " << file_name.value();
     return false;
   }
 
@@ skipping 17 matching lines @@
     munmap(data_, length_);
   if (file_ != -1)
     close(file_);
 
   data_ = NULL;
   length_ = 0;
   file_ = -1;
 }
 
 } // namespace file_util