Add patch to make iframe sandboxed by default.

iframes are now sandboxed by default except for following cases:

1. host is localhost.
2. scheme is other than http and file.
3. nested iframes (e.g. iframes in iframe).
Add patch for the accelerator.

1. Allow Ctrl+Alt accelerators on Windows.
2. Fix showing text for code key F2 to F22.
Add patch to disable sandbox in SharedWorker.
Add patch to fix the wrong hittest in child.
Add patch to suppress to spam loggings from mojo.

Imported from:
http://src.chromium.org/viewvc/chrome/trunk/src/mojo/system/channel.cc?revision=275141