Disable support for swapped out RenderFrame(Host) and add instrumentation

This CL is aiming to collect information about cases where the
FocusController's focused frame is set to a RemoteFrame. This is the root
cause of the crash in https://crbug.com/541578.

BUG=541578, 357747

Review URL: https://codereview.chromium.org/1397323004

Cr-Commit-Position: refs/heads/master@{#353847}
2 files changed