leveldb: Added dumpfile to *.gyp

Needed for leveldb_main utility program to link.

Review URL: https://codereview.chromium.org/802633003

Cr-Commit-Position: refs/heads/master@{#308476}

third_party/leveldatabase/leveldatabase.gyp

@@ -92,10 +92,11 @@
         'src/db/db_impl.h',
         'src/db/db_iter.cc',
         'src/db/db_iter.h',
-        'src/db/filename.cc',
-        'src/db/filename.h',
         'src/db/dbformat.cc',
         'src/db/dbformat.h',
+        'src/db/dumpfile.cc',
+        'src/db/filename.cc',
+        'src/db/filename.h',
         'src/db/log_format.h',
         'src/db/log_reader.cc',
         'src/db/log_reader.h',
@@ -119,6 +120,7 @@
         'src/include/leveldb/cache.h',
         'src/include/leveldb/comparator.h',
         'src/include/leveldb/db.h',
+        'src/include/leveldb/dumpfile.h',
         'src/include/leveldb/env.h',
         'src/include/leveldb/filter_policy.h',
         'src/include/leveldb/iterator.h',