[sql] Increase database chunk size for large databases.

[sql] Increase database chunk size for large databases.

SQLite implements a hint to request the databases be truncated or
expanded to multiples of a chunk size.  This was originally implemented
to reduce filesystem fragmentation, and it also can improve performance
because file sizes don't vary as much.

For a memory-mapped database, it also reduces the number of calls to
adjust the memory map when the database size changes.

BUG=551108
Committed: https://crrev.com/5dac334f21d99d9f97d9c7bbfbba40c8e872545b
Cr-Commit-Position: refs/heads/master@{#358121}

[Scott Hess - ex-Googler, 2015-11-04 23:37:29]

shess@chromium.org changed reviewers:
+ rmcilroy@chromium.org

[rmcilroy, 2015-11-05 11:39:30]

lgtm

[Scott Hess - ex-Googler, 2015-11-05 18:50:04]

rebase

[Scott Hess - ex-Googler, 2015-11-05 19:02:58]

The CQ bit was checked by shess@chromium.org

[Scott Hess - ex-Googler, 2015-11-05 19:02:58]

The patchset sent to the CQ was uploaded after l-g-t-m from
rmcilroy@chromium.org
Link to the patchset: https://codereview.chromium.org/1402373007/#ps20001
(title: "rebase")

[commit-bot: I haz the power, 2015-11-05 19:04:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402373007/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402373007/20001

[commit-bot: I haz the power, 2015-11-05 19:16:41]

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

[commit-bot: I haz the power, 2015-11-05 19:16:41]

Try jobs failed on following builders:
  android_arm64_dbg_recipe on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_arm64_d...)
  linux_android_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_android_r...)

[Scott Hess - ex-Googler, 2015-11-05 19:20:32]

The CQ bit was checked by shess@chromium.org

[commit-bot: I haz the power, 2015-11-05 19:21:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402373007/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402373007/20001

[commit-bot: I haz the power, 2015-11-05 19:36:35]

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

[commit-bot: I haz the power, 2015-11-05 19:36:36]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Scott Hess - ex-Googler, 2015-11-05 20:09:42]

On 2015/11/05 19:36:36, commit-bot: I haz the power wrote:
> Try jobs failed on following builders:
>   mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
>
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

Sigh.  Earlier fail was obvious breakage in a Java checking which had been
reverted.  This one appears to be Telemetry, which doesn't seem likely to have
any intersection with the actual CL, so like a good monkey I'm going to keep
pressing the button and hope for a reward.

[Scott Hess - ex-Googler, 2015-11-05 20:09:47]

The CQ bit was checked by shess@chromium.org

[commit-bot: I haz the power, 2015-11-05 20:10:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402373007/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402373007/20001

[commit-bot: I haz the power, 2015-11-05 20:47:49]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-05 20:48:36]

Patchset 2 (id:??) landed as
https://crrev.com/5dac334f21d99d9f97d9c7bbfbba40c8e872545b
Cr-Commit-Position: refs/heads/master@{#358121}