Reland #1 "ipc: Add a new field num_brokered_attachments to the message header."

This otherwise innocuous CL is causing an unusual crash in Canary. At first
glance, the crash appears related to IPC, but further digging indicates that
it's probably related to corruption of a ResourceBuffer. I've updated that class
to use CHECKs instead of DCHECKs https://codereview.chromium.org/1325153002/.

I expect this CL to cause ~100 crashes in the next Chrome Canary. I intend to
revert this CL after a single Canary release. This CL will help me better
diagnose the exact nature of the crash.

BUG=493414

Review URL: https://codereview.chromium.org/1330563002

Cr-Commit-Position: refs/heads/master@{#347250}


CrOS-Libchrome-Original-Commit: d32c32bef61d80f68208e550ace18f50f1c498d1
2 files changed
tree: 9a3f2e627d22a97c1933caffba6074137f1e7376
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/