Move fast and break things

Summary:
Broke the compile when I removed purge_log_after_memtable_flush.

sorrybus

Test Plan: make db_bench works now

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14037

db/db_bench.cc

@@ -480,10 +480,6 @@ DEFINE_string(merge_operator, "", "The merge operator to use with the database."
               " database The possible merge operators are defined in"
               " utilities/merge_operators.h");
 
-DEFINE_bool(purge_log_after_memtable_flush,
-            rocksdb::Options().purge_log_after_memtable_flush,
-            "");
-
 namespace rocksdb {
 
 // Helper for quickly generating random data.
@@ -1336,8 +1332,6 @@ class Benchmark {
         );
         break;
     }
-    options.purge_log_after_memtable_flush =
-      FLAGS_purge_log_after_memtable_flush;
     if (FLAGS_max_bytes_for_level_multiplier_additional_v.size() > 0) {
       if (FLAGS_max_bytes_for_level_multiplier_additional_v.size() !=
           (unsigned int)FLAGS_num_levels) {

doc/index.html

@@ -704,9 +704,6 @@ <h1>Purging WAL files</h1>
 checks will be performed with ttl being first.
 </ul>
 
-You can completely disable WAL file purging by setting
-<code>Options::purge_log_after_memtable_flush</code> to false.
-
 <h1>Other Information</h1>
 <p>
 Details about the <code>rocksdb</code> implementation may be found in