Update update engine to compile and use libchrome-180609.

Made the following fixes:
- base/eintr_wrapper.h -> base/posix/eintr_wrapper.h
- base/string_tokenizer.h -> base/strings/string_tokenizer.h
- Switched JSONReader->JsonToValue to use JSONReader->ReadToValue.

BUG=chromium-os:39847
TEST=unittests + run through image_to_live

Change-Id: Iffa0a3af4a065fac40460d8c1c2ed5c9b6e9ed07
Reviewed-on: https://gerrit.chromium.org/gerrit/44098
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: Chris Sosa <sosa@chromium.org>
diff --git a/utils.cc b/utils.cc
index fee3439..2276ac4 100644
--- a/utils.cc
+++ b/utils.cc
@@ -19,10 +19,10 @@
 
 #include <algorithm>
 
-#include <base/eintr_wrapper.h>
 #include <base/file_path.h>
 #include <base/file_util.h>
 #include <base/logging.h>
+#include <base/posix/eintr_wrapper.h>
 #include <base/rand_util.h>
 #include <base/string_number_conversions.h>
 #include <base/string_util.h>