sqlite: Enable SQLITE_ENABLE_BATCH_ATOMIC_WRITE.

When the underlying filesystem supports batch atomic writes, SQLite
does not write a rollback journal. This reduces write amplification on
filesystems that implement their own journal, improving performance and
reducing SSD wear. This feature is currently supported on f2fs, which is
widely deployed on Android, and may be deployed on Chrome OS.

Bug: 901872
Change-Id: I746242e1e5f03319ae7fd61b224ec66723e9c61d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1547336
Auto-Submit: Victor Costan <pwnall@chromium.org>
Reviewed-by: Chris Mumford <cmumford@google.com>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#646372}

third_party/sqlite/BUILD.gn

@@ -20,6 +20,10 @@ import("//third_party/protobuf/proto_library.gni")
 # https://www.sqlite.org/compile.html
 config("chromium_sqlite3_compile_options") {
   defines = [
+    # Skip writing transaction rollback journals on f2fs.
+    # f2fs tends to be used on Android, and may be used on ChromeOS.
+    "SQLITE_ENABLE_BATCH_ATOMIC_WRITE",
+
     "SQLITE_ENABLE_FTS3",
 
     # New unicode61 tokenizer with built-in tables.