Refactor: unsigned long long -> uint64_t in third_party/blink/renderer/modules/webdatabase

- unsigned long long -> uint64_t.
- No logic changes.
- Reference: https://google.github.io/styleguide/cppguide.html#Integer_Types

Bug: 929980
Change-Id: Ib8df69a6d63b7ee8f90a48ad9de13eb27cc0b819
Reviewed-on: https://chromium-review.googlesource.com/c/1468827
Auto-Submit: Darwin Huang <huangdarwin@chromium.org>
Commit-Queue: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631542}
7 files changed