AU: Many minor cleanup changes

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"
@@ skipping 10 matching lines @@
 }
 }  // 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));
-  const string version(GetLsbValue("GOOGLE_RELEASE"));
+  const string version(GetLsbValue("CHROMEOS_RELEASE_VERSION", ""));
   const string sp(version + "_" + GetMachineType());
-  const string track(GetLsbValue("GOOGLE_TRACK"));
+  const string track(GetLsbValue("CHROMEOS_RELEASE_TRACK", ""));
+  const string update_url(GetLsbValue("CHROMEOS_AUSERVER",
+                                      UpdateCheckParams::kUpdateUrl));
 
   UpdateCheckParams out(machine_id,  // machine_id
                         machine_id,  // user_id (use machine_id)
                         UpdateCheckParams::kOsPlatform,
                         UpdateCheckParams::kOsVersion,
                         sp,  // e.g. 0.2.3.3_i686
                         UpdateCheckParams::kAppId,
                         version,  // app version (from lsb-release)
-                        "en-US",  //lang
-                        track);  // track
+                        "en-US",  // lang
+                        track,  // track
+                        UpdateCheckParams::kUpdateUrl);
 
   CHECK(HasOutputPipe());
   SetOutputObject(out);
   completer.set_success(true);
 }
 
 namespace {
 const size_t kGuidDataByteLength = 128 / 8;
 const string::size_type kGuidStringLength = 38;
 // Formats 16 bytes (128 bits) of data as a GUID:
@@ skipping 28 matching lines @@
     TEST_AND_RETURN_FALSE_ERRNO(rc > 0);
     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 OmahaRequestPrepAction::GetLsbValue(
+    const string& key, const string& default_value) const {
   string files[] = {string(utils::kStatefulPartition) + "/etc/lsb-release",
                     "/etc/lsb-release"};
   for (unsigned int i = 0; i < arraysize(files); i++) {
+    // TODO(adlr): make sure files checked are owned as root (and all
+    // their parents are recursively, too).
     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
     }
     if (pos == string::npos)
       continue;
     pos += key.size() + 1;  // advance past the key and the '='
     string::size_type endpos = file_data.find('\n', pos);
     string::size_type length =
         (endpos == string::npos ? string::npos : endpos - pos);
     return file_data.substr(pos, length);
   }
   // not found
-  return "";
+  return default_value;
 }
 
-std::string OmahaRequestPrepAction::GetMachineType() const {
+string OmahaRequestPrepAction::GetMachineType() const {
   struct utsname buf;
   string ret;
   if (uname(&buf) == 0)
     ret = buf.machine;
   return ret;
 }
 
 }  // namespace chromeos_update_engine