[update_engine] Update to use not-hideously-old logging API from chrome

BUG=None
TEST=compile

Change-Id: Ieed8952b6806a72b59e16c1579f7293b6a98157a

Review URL: http://codereview.chromium.org/3170010
diff --git a/install_plan.h b/install_plan.h
index 9fc6ead..19fee8a 100644
--- a/install_plan.h
+++ b/install_plan.h
@@ -6,7 +6,7 @@
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_INSTALL_PLAN_H__
 
 #include <string>
-#include "chromeos/obsolete_logging.h"
+#include "base/logging.h"
 
 // InstallPlan is a simple struct that contains relevant info for many
 // parts of the update system about the install that should happen.