Change hash table capacity defaults.

Change hash table capacity defaults.

The rationale is: callsites of HashTable::New without the capacity_option
argument specify an initial size of the hash table. It's surprising that it's
automatically doubled. This does not change the size of the slow mode object
property dictionary, as it allocates via Dictionary::New.

BUG=chromium:481129
LOG=N

[Yang, 2015-05-20 12:18:48]

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

[Yang, 2015-05-20 12:18:49]

The rationale is: callsites of HashTable::New without the capacity_option
argument specify an initial size of the hash table. It's surprising that it's
automatically doubled. This does not change the size of the slow mode object
property dictionary, as it allocates via Dictionary::New.

[mvstanton, 2015-05-20 12:36:23]

lgtm. nit: add that nice rationale to the CL description so it's in the tree :).

[Yang, 2015-05-20 13:21:48]

The CQ bit was checked by yangguo@chromium.org

[commit-bot: I haz the power, 2015-05-20 13:21:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1146913002/1

[commit-bot: I haz the power, 2015-05-20 14:10:11]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-05-20 14:10:12]

Try jobs failed on following builders:
  v8_linux64_avx2_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel/builds/545)