Revert of Add ZipReader::ExtractCurrentEntry with a delegate interface.

Revert of Add ZipReader::ExtractCurrentEntry with a delegate interface. (patchset #2 id:40001 of https://codereview.chromium.org/1014653002/)

Reason for revert:
There are uninitialized reads on the DrMemory bots in zlib ZipTests. They have very little information, and there is no history available due to a bot problem.

Experimentally reverting this CL to see if it helps.

Original issue's description:
> Add ZipReader::ExtractCurrentEntry with a delegate interface.
>
> This change gives consumers of ZipReader a way to have the current entry
> streamed to them via a Delegate interface. It also:
>
> - Reduces duplication in the ExtractCurrentEntry* functions.
> - Uses the heap rather than the stack for intermediate buffers.
> - Changes ExtractCurrentEntryToFd to ExtractCurrentEntryToFile, making
>   it cross-platform in the process.
>
> BUG=462584
>
> Committed: https://crrev.com/2919be01ff758875fc7161f6b41f4461518c1213
> Cr-Commit-Position: refs/heads/master@{#320948}

TBR=hshi@chromium.org,grt@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=462584
Committed: https://crrev.com/1369bc06458c9e803307ddc7aaec0d71e4a938ab
Cr-Commit-Position: refs/heads/master@{#321059}

[benwells, 2015-03-18 02:31:13]

Created Revert of Add ZipReader::ExtractCurrentEntry with a delegate interface.

[commit-bot: I haz the power, 2015-03-18 02:31:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1016813004/1

[commit-bot: I haz the power, 2015-03-18 02:32:19]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-18 02:33:18]

Patchset 1 (id:??) landed as
https://crrev.com/1369bc06458c9e803307ddc7aaec0d71e4a938ab
Cr-Commit-Position: refs/heads/master@{#321059}