BIND 10 #2973: write tests for ZoneWriter::install

[BIND 10 Development]

#2973: write tests for ZoneWriter::install
-------------------------------------+-------------------------------------
                   Reporter:         |                 Owner:
  jinmei                             |                Status:  new
                       Type:         |             Milestone:  Next-Sprint-
  defect                             |  Proposed
                   Priority:         |              Keywords:
  medium                             |             Sensitive:  0
                  Component:  data   |           Sub-Project:  DNS
  source                             |  Estimated Difficulty:  0
               CVSS Scoring:         |           Total Hours:  0
            Defect Severity:  N/A    |
Feature Depending on Ticket:         |
        Add Hours to Ticket:  0      |
                  Internal?:  0      |
-------------------------------------+-------------------------------------
 complete this FIXME:

 {{{#!cpp
     // FIXME: This retry is currently untested, as there seems to be no
     // reasonable way to create a zone table segment with non-local memory
     // segment. Once there is, we should provide the test.
 }}}

 I guess it was left open because at that time `ZoneWriter` was an
 abstract class and cannot easily be instantiated.  It's not the case
 anymore, so we should be able to test this (even if we cannot reliably
 cause `MemorySegmentGrown`).  I suggest doing something similar to
 `ZoneDataLoaterTest.relocate`.

-- 
Ticket URL: <http://bind10.isc.org/ticket/2973>
BIND 10 Development <http://bind10.isc.org>
BIND 10 Development