Use GlobalFrameRoutingId for shared worker clients

This simplifies the code a bit and removes any possibilities of
mixing RenderProcessHost IDs and frame routing IDs.

Change-Id: I0d7c8df9b6ebc9c7e20d5fbc6f36074125761f74
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1977966
Commit-Queue: Patrick Monette <[email protected]>
Reviewed-by: Emily Stark <[email protected]>
Reviewed-by: Matt Falkenhagen <[email protected]>
Reviewed-by: Hiroki Nakagawa <[email protected]>
Reviewed-by: Sigurður Ásgeirsson <[email protected]>
Cr-Commit-Position: refs/heads/master@{#729958}
17 files changed