UpdateManager: Adjustments for cpplint.

- Rename header file guards.

- Added missing #includes.

Note that the linter still barks about C++11-style curly-braced member
initialization; there are abundant uses of this and we should probably
upstream a change to accommodate that.

BUG=None
TEST=Builds.

Change-Id: Icccc88e6e56e56f644536147cd88ae92462a1495
Reviewed-on: https://chromium-review.googlesource.com/205894
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
diff --git a/update_manager/generic_variables.h b/update_manager/generic_variables.h
index 5831463..9d00b7e 100644
--- a/update_manager/generic_variables.h
+++ b/update_manager/generic_variables.h
@@ -6,8 +6,8 @@
 // used by any state provider to implement simple variables to avoid repeat the
 // same common code on different state providers.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_
+#ifndef UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_
+#define UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_
 
 #include <string>
 
@@ -203,4 +203,4 @@
 
 }  // namespace chromeos_update_manager
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_
+#endif  // UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_