tree f4ec9c85a3a96e0926ace344908f72a770665125
parent 86f1360947e6a468342483c688fbf534c591f51a
author Andrey Pronin <apronin@chromium.org> 1513390399 -0800
committer ChromeOS Commit Bot <chromeos-commit-bot@chromium.org> 1517350934 +0000

chaps: create ChapsProxy w/o AtExitManager when possible

ChapsProxy is used by PKCS#11 interface and TokenManagerClient.
Before this change, each ChapsProxy creation was also instantiating a
shadowing AtExitManager (ChapsProxy operation relies on having
AtExitManager).

As a result, overlapping ChapsProxy instances led to AtExitManager
crashes during destruction, since AtExitManagers assume strictly
nested lifecycles. Here overlapping = when object A is
constructed ahead of object B, and then also destructed ahead of
object B. Nested = object A is created before object B, and then
destroyed after object B, so object B life is fully nested inside
object A life.

And we may have overlapping lifecycles at least for TokenManagerClients.

This change:
1) Allows the creators of ChapsProxy to specify if a shadowing
AtExitManager is needed, or the creator knows that AtExitManager already
exists and additional ones are thus not needed;
2) Adds a requirement that all users of TokenClientManager must have
AtExitManager already instantiated at upper calling levels, so
TokenClientManager always creates ChapsProxy w/o a shadowing
AtExitManager.
3) Adds AtExitManager at the top level for some utilities and tests, so
that they also create ChapsProxy w/o a shadowing AtExitManager.

This eliminates all known situations when ChapsProxy's AtExitManager
lifecycles can be overlapping. More details on the BUG.

BUG=b:69871115
BUG=chromium:794403
TEST=1) Unit tests.
     2) chaps_client works.
     3) The following code doesn't crash:
  base::AtExitManager at_exit;
  {
    TokenManagerClient client1;
    TokenManagerClient client2;

    client2.Connect();
    client1.Connect();

    // will be destructed in the order:
    // client2.~TokenManagerClient()
    // client1.~TokenManagerClient()
  }

Change-Id: Id5ac8fa5a2112e614b74b120cd89e4baacaadff2
Reviewed-on: https://chromium-review.googlesource.com/831349
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Eric Caruso <ejcaruso@chromium.org>
(cherry picked from commit cf1f5c45845d47a949525f1d17da329f0f549e67)
Reviewed-on: https://chromium-review.googlesource.com/894265
Reviewed-by: Andrey Pronin <apronin@chromium.org>
Commit-Queue: Andrey Pronin <apronin@chromium.org>