commit abc4b8f035c491f976be736373f50c3cac33a7a6
author Yohei Yukawa <yukawa@google.com> Mon Feb 29 13:35:59 2016 -0800
committer Yohei Yukawa <yukawa@google.com> Mon Feb 29 13:35:59 2016 -0800
tree 22244557d209ac12cc6cbb3f9a2d5dbfc8e66549
parent 82197c33a23a130acd93dcf54e70138a7e7ba970

Revert "InputConnectionWrapper never supports null target."

This reverts commit 90bd36363c5738b3f526aa1f1d44f432236300a0.

Seems that the semantics of InputConnectionWrapper#setTarget() is more
complicated than I thought.  At least the following cases have worked
fine.

  case 1:
    InputConnectionWrapper wrapper =
            new InputConnectionWrapper(null, false);
    wrapper.SetTarget(ic);
    ...

  case 2:
    InputConnectionWrapper wrapper =
            new InputConnectionWrapper(null, true);
    wrapper.SetTarget(ic);
    ...

  case 3:
    InputConnectionWrapper wrapper =
            new InputConnectionWrapper(ic, true);
    wrapper.SetTarget(null);
    wrapper.SetTarget(ic2);
    ...

The previous code did not intended to break existing code.  Let's revert
it we decide how to deal with above cases.

Bug: 27407697
Change-Id: I8bc84d484ab0b27a02e74f11110430f70646e69a