GitLab

The metro_driver should not block the UI thread while waiting for the Chrome browser IPC channel to be initialized.

This causes the taskbar to become unresponsive for a bit on Windows 7. Windows 8 also has the same
problem. However it is not as visible as on Windows 7.

Fix is to do the IPC channel dance in a timer.

BUG=417100
R=cpu

Review URL: https://codereview.chromium.org/593353003

Cr-Commit-Position: refs/heads/master@{#297058}