[webnfc] Restrict NFC message size to 32KB

This patch limits maximum NFC message size for nfc.push() operation to
32KB. The 32KB limit is selected based on several factors: capacity of
consumer NFC tags, data transfer rate and IPC mechanism that is used by
mojo service. Layout test is modified to test that promise is rejected
for nfc.push() operation when message size exceeds 32KB.

BUG=520391

Review-Url: https://codereview.chromium.org/2524743002
Cr-Commit-Position: refs/heads/master@{#434131}
3 files changed