IPC::ChannelMojo: Don't supress MOJO_RESULT_FAILED_PRECONDITION

The error should be reported to IPC::Listener as it is a
signal of the dead peer. Without this, the browser cannot
detect renderer crashes.

TEST=browser_tests (with ChannelMojo enabled)
[email protected],[email protected]
BUG=none

Review URL: https://codereview.chromium.org/453643003

Cr-Commit-Position: refs/heads/master@{#288442}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288442 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed