AU: Try delta updates first, then full updates

src/platform/update_engine/omaha_request_prep_action.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 "update_engine/omaha_request_prep_action.h"
 #include <sys/utsname.h>
 #include <errno.h>
 #include <string>
 #include "base/string_util.h"
 #include "update_engine/utils.h"
 
 using std::string;
 
 // This gathers local system information and prepares info used by the
 // update check action.
 
 namespace {
 const string OmahaIdPath() {
-  return chromeos_update_engine::utils::kStatefulPartition + "/etc/omaha_id";
+  return string(chromeos_update_engine::utils::kStatefulPartition) +
+      "/etc/omaha_id";
 }
 }  // namespace {}
 
 namespace chromeos_update_engine {
 
 void OmahaRequestPrepAction::PerformAction() {
   // TODO(adlr): honor force_full_update_
   ScopedActionCompleter completer(processor_, this);
   string machine_id;
   TEST_AND_RETURN(GetMachineId(&machine_id));
@@ skipping 52 matching lines @@
     bytes_read += rc;
   }
   string guid = GuidFromData(buf);
   TEST_AND_RETURN_FALSE(
       utils::WriteFile(omaha_id_path.c_str(), guid.data(), guid.size()));
   *out_id = guid;
   return true;
 }
 
 std::string OmahaRequestPrepAction::GetLsbValue(const std::string& key) const {
-  string files[] = {utils::kStatefulPartition + "/etc/lsb-release",
+  string files[] = {string(utils::kStatefulPartition) + "/etc/lsb-release",
                     "/etc/lsb-release"};
   for (unsigned int i = 0; i < arraysize(files); i++) {
     string file_data;
     if (!utils::ReadFileToString(root_ + files[i], &file_data))
       continue;
     string::size_type pos = 0;
     if (!utils::StringHasPrefix(file_data, key + "=")) {
       pos = file_data.find(string("\n") + key + "=");
       if (pos != string::npos)
         pos++;  // advance past \n
@@ skipping 12 matching lines @@
 
 std::string OmahaRequestPrepAction::GetMachineType() const {
   struct utsname buf;
   string ret;
   if (uname(&buf) == 0)
     ret = buf.machine;
   return ret;
 }
 
 }  // namespace chromeos_update_engine