update_engine: Merge remote-tracking branch 'cros/upstream' into cros/master

Since libchrome in AOSP is ahead of CrOS I had to guard against BASE_VER in a
few places to satisfy older libchromes.

file_fetcher.cc is now needed in delta_generator.

A few unittests need to be run as root.

BUG=chromium:916593
TEST=unittest
TEST=cros_generate_update_payload
TEST=cros flash
CQ-DEPEND=CL:1399261

Change-Id: If3497549e88e559f8ecc38f414259b9c774f4a44
diff --git a/common_service.cc b/common_service.cc
index 6420b65..88ead28 100644
--- a/common_service.cc
+++ b/common_service.cc
@@ -50,7 +50,11 @@
 namespace {
 // Log and set the error on the passed ErrorPtr.
 void LogAndSetError(ErrorPtr* error,
+#if BASE_VER < 576279
                     const tracked_objects::Location& location,
+#else
+                    const base::Location& location,
+#endif
                     const string& reason) {
   brillo::Error::AddTo(error,
                        location,