Give ComputeCapacityForSerialization a minimum capacity

Give ComputeCapacityForSerialization a minimum capacity

This avoids DCHECK failures when passing 0 as the at_least_space_for
argument to HashTableBase::New (allowing converting code from non-serialized
to serialized without changing callsites).

Committed: https://crrev.com/090c78219f57a96913af05b78414fa2aeea3a016
Cr-Commit-Position: refs/heads/master@{#28321}

[adamk, 2015-05-07 21:24:58]

adamk@chromium.org changed reviewers:
+ yangguo@chromium.org

[adamk, 2015-05-07 21:24:58]

Ran into this when trying to add a new ObjectHashTable member to native
contexts.

[Yang, 2015-05-08 04:58:22]

On 2015/05/07 21:24:58, adamk wrote:
> Ran into this when trying to add a new ObjectHashTable member to native
> contexts.

Lgtm

[adamk, 2015-05-08 15:01:24]

The CQ bit was checked by adamk@chromium.org

[commit-bot: I haz the power, 2015-05-08 15:01:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1134573002/1

[commit-bot: I haz the power, 2015-05-08 15:03:41]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-08 15:03:49]

Patchset 1 (id:??) landed as
https://crrev.com/090c78219f57a96913af05b78414fa2aeea3a016
Cr-Commit-Position: refs/heads/master@{#28321}