Add extra parameter to BrowserChildProcessCrashed to pass the exit_code at time of crash/termination.
Wire this into all the existing callers.
Add a new child process watcher in chrome to be notified on child process crashes. This will confirm whether users with RESULT_CODE_INVALID_SANDBOX_STATE are crashing on background start (--no-startup-window) or not. This also adds required framework to paint a sad tab UI from this class in the future.
BUG=472324, 453541
TEST=Apply patch in http://pastebin.com/uEDxngBa and verify histogram ChildProcess.InvalidSandboxStateCrash.NoStartupWindow is recorded.
Review URL: https://codereview.chromium.org/
1067733006
Cr-Commit-Position: refs/heads/master@{#327380}