Fixing incorrect variable name in error code path.
Fixing incorrect variable name in error code path.

content_length -> content_len

BUG=None
TEST=None
R=mcgrathr@chromium.org

Review URL: https://chromiumcodereview.appspot.com/10700010

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@9051 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client