Revert of "[sql] Remove part of WebDatabase SQLite patch." (patchset #1 of https://codereview.chromium.org/1473963002 )

Reason for revert:

Unfortunately, this seems to have introduced flaky shutdown crashes on storage/websql/open-database-creation-callback.html across bots,

 http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=storage%2Fwebsql%2Fopen-database-creation-callback.html

 http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Trusty/builds/5769

Original issue's description:
> [sql] Remove part of WebDatabase SQLite patch.
>
> findReusableFd() calls stat() on the filename to determine the inode
> and device to figure out if a previously-closed file descriptor can be
> reused.  Since WebDatabase file names are resolved by the browser,
> this stat() can never succeed in the renderer, thus there is no point
> to calling the function.
>
> This SQLite code path is an optimization to reduce close/open churn,
> it is not necessary for correct operation.
>
> BUG=none
>
> Review URL: https://codereview.chromium.org/1473963002
> Cr-Commit-Position: refs/heads/master@{#361825}

TBR=shess@chromium.org,michaeln@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1485603003

Cr-Commit-Position: refs/heads/master@{#362112}
6 files changed