Enable shared proto database by default.

BUG=870813

Change-Id: I0203d93bcc2b38358804f5f6bf15379598016027
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2467059Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Commit-Queue: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816427}

components/leveldb_proto/internal/leveldb_proto_feature_list.cc

@@ -7,6 +7,6 @@
 namespace leveldb_proto {
 
 const base::Feature kProtoDBSharedMigration{"ProtoDBSharedMigration",
-                                            base::FEATURE_DISABLED_BY_DEFAULT};
+                                            base::FEATURE_ENABLED_BY_DEFAULT};
 
 }  // namespace leveldb_proto