Clipboard: Opt out of PNG Encoding filters.

Set the PNG encoder's FilterFlag to kNone from the default kAll.

The clipboard should prefer faster encode time over encode size for image/png,
so set all clipboard image decoding to skip testing of different PNG encoding
filters, which takes a lot of time for not too much compression ratio benefit
in the common case.

Benchmarking with a random-pixel 8k by 4k px image
(https://www.photopea.com/clipboard_img.html), and fZLibLevel = 1, here's some
encode times (seconds) varying flags:
* kNone: 2.98 (trials: 3.00814, 2.98265, 2.99636, 2.9877, 2.96517, 2.99467)
* kSub:  3.03 (trials: 3.02345, 3.04085, 3.00886, 3.0587, 3.03992, 3.02549)
* kAll:  4.12 (trials: 4.12813, 4.12552, 4.08524, 4.13283, 4.15013, 4.11719)

Using kNone would save ~28% encode time over the current kAll.
This will be most visible for pasting of extremely large photos.

Bug: 1004867
Change-Id: I37a848498da425249e57171ae2ca3f0595c6b793
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1827953
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700598}
DataObjectItem* DataObjectItem::CreateFromClipboard(const String& type,
                                                    uint64_t sequence_number) {
  if (type == kMimeTypeImagePng) {
    return MakeGarbageCollected<DataObjectItem>(kFileKind, type,
                                                sequence_number);
  }
  return MakeGarbageCollected<DataObjectItem>(kStringKind, type,
                                              sequence_number);
}

DataObjectItem* DataObjectItem::CreateFromClipboard(const String& type,
                                                    uint64_t sequence_number) {
  if (type == kMimeTypeImagePng) {
    return MakeGarbageCollected<DataObjectItem>(kFileKind, type,
                                                sequence_number);
  }
  return MakeGarbageCollected<DataObjectItem>(kStringKind, type,
                                              sequence_number);
}
