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/file_descriptor.cc b/file_descriptor.cc
index a064925..255307d 100644
--- a/file_descriptor.cc
+++ b/file_descriptor.cc
@@ -8,7 +8,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
-#include <base/eintr_wrapper.h>
+#include <base/posix/eintr_wrapper.h>
 
 namespace chromeos_update_engine {