Fix cpplint errors.

The only non-obvious change here is the switch from dynamic_cast to
static_cast in three cases of down-casting in UpdateAttempter.
dynamic_cast is banned by style, nor does it add any safety in this
particular case (subsequent code dereferences the result right away
without checking whether it's null).

BUG=None
TEST=None

Change-Id: I9d49b46362feaf9c6fa13b2715ebe9fe50308a9a
Reviewed-on: https://chromium-review.googlesource.com/207470
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
diff --git a/simple_key_value_store.h b/simple_key_value_store.h
index eb5a4e2..a648cd4 100644
--- a/simple_key_value_store.h
+++ b/simple_key_value_store.h
@@ -6,8 +6,8 @@
 // key value store. Each key/value pair is stored on its own line and
 // separated by the first '=' on the line.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
+#ifndef UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
+#define UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
 
 #include <map>
 #include <string>
@@ -50,4 +50,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
+#endif  // UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_