Revert "Update includes for webrtc/{base => rtc_base} rename (2/3)"

This reverts commit c3771cc4d37f5573fe53b7c7cff295a4f0f9560f.
(breaks downstream internal project)

BUG=webrtc:7634
NOTRY=True
NOPRESUBMIT=True

Review-Url: https://codereview.webrtc.org/2972463002 .
Cr-Commit-Position: refs/heads/master@{#18873}
diff --git a/webrtc/system_wrappers/include/aligned_array.h b/webrtc/system_wrappers/include/aligned_array.h
index 7cc1c02..71fefea 100644
--- a/webrtc/system_wrappers/include/aligned_array.h
+++ b/webrtc/system_wrappers/include/aligned_array.h
@@ -11,7 +11,7 @@
 #ifndef WEBRTC_SYSTEM_WRAPPERS_INCLUDE_ALIGNED_ARRAY_
 #define WEBRTC_SYSTEM_WRAPPERS_INCLUDE_ALIGNED_ARRAY_
 
-#include "webrtc/rtc_base/checks.h"
+#include "webrtc/base/checks.h"
 #include "webrtc/system_wrappers/include/aligned_malloc.h"
 
 namespace webrtc {