NaCl: update OWNERS

The OWNERS file for the NaCl SDK and documentation were out of date.

R=sbc@chromium.org, binji@chromium.org, sehr@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/864403002

Cr-Commit-Position: refs/heads/master@{#312638}

native_client_sdk/OWNERS

@@ -1,6 +1,5 @@
+binji@chromium.org
 bradnelson@chromium.org
 noelallen@chromium.org
-erikkay@chromium.org
-binji@chromium.org
 sbc@chromium.org
-nfullagar@chromium.org
+sehr@chromium.org

native_client_sdk/src/doc/OWNERS

@@ -1,3 +1,5 @@
+binji@chromium.org
+jfb@chromium.org
+jmedley@chromium.org
+sbc@chromium.org
 sehr@chromium.org
-eliben@chromium.org
-awatson@chromium.org