Move KeyValueStore to libchromeos

KeyValueStore is a key-value dictionary used to access and store settings
in a .conf file. It supports bool and strings only.

BUG=chromium:416932
TEST=FEATURES=test emerge-link libchromeos update_engine

Change-Id: I34a3add5536588ea1025976de659ad77ac6d8b39
Reviewed-on: https://chromium-review.googlesource.com/219552
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: David Pursell <dpursell@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
Tested-by: Alex Deymo <deymo@chromium.org>
diff --git a/hwid_override.cc b/hwid_override.cc
index 768c86b..0ec949f 100644
--- a/hwid_override.cc
+++ b/hwid_override.cc
@@ -9,8 +9,7 @@
 
 #include <base/files/file_path.h>
 #include <base/files/file_util.h>
-
-#include "update_engine/simple_key_value_store.h"
+#include <chromeos/key_value_store.h>
 
 using std::map;
 using std::string;
@@ -24,8 +23,8 @@
 HwidOverride::~HwidOverride() {}
 
 std::string HwidOverride::Read(const base::FilePath& root) {
-  KeyValueStore lsb_release;
-  lsb_release.Load(root.value() + "/etc/lsb-release");
+  chromeos::KeyValueStore lsb_release;
+  lsb_release.Load(base::FilePath(root.value() + "/etc/lsb-release"));
   string result;
   if (lsb_release.GetString(kHwidOverrideKey, &result))
     return result;