AU: Push seeks in http fetching to the progress percentage.

prefs.cc

 // Copyright (c) 2010 The Chromium OS 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 "update_engine/prefs.h"
 
 #include <base/file_util.h>
 #include <base/logging.h>
 #include <base/string_number_conversions.h>
 #include <base/string_util.h>
@@ skipping 17 matching lines @@
     "update-state-signed-sha-256-context";
 
 bool Prefs::Init(const FilePath& prefs_dir) {
   prefs_dir_ = prefs_dir;
   return true;
 }
 
 bool Prefs::GetString(const string& key, string* value) {
   FilePath filename;
   TEST_AND_RETURN_FALSE(GetFileNameForKey(key, &filename));
-  TEST_AND_RETURN_FALSE(file_util::ReadFileToString(filename, value));
+  if (!file_util::ReadFileToString(filename, value)) {
+    PLOG(INFO) << "Unable to read prefs from " << filename.value()
+               << ". This is likely harmless.";
+    return false;
+  }
   return true;
 }
 
 bool Prefs::SetString(const std::string& key, const std::string& value) {
   FilePath filename;
   TEST_AND_RETURN_FALSE(GetFileNameForKey(key, &filename));
   TEST_AND_RETURN_FALSE(file_util::CreateDirectory(filename.DirName()));
   TEST_AND_RETURN_FALSE(
       file_util::WriteFile(filename, value.data(), value.size()) ==
       static_cast<int>(value.size()));
@@ skipping 18 matching lines @@
   for (size_t i = 0; i < key.size(); ++i) {
     char c = key.at(i);
     TEST_AND_RETURN_FALSE(IsAsciiAlpha(c) || IsAsciiDigit(c) ||
                           c == '_' || c == '-');
   }
   *filename = prefs_dir_.Append(key);
   return true;
 }
 
 }  // namespace chromeos_update_engine