GitLab

Introduces an LRU cache for prelaunching renderers. This class creates a
pool of prelaunched renderers for the N most recently closed pages.

Bug: internal b/77879457
Test: cast_shell_unittests
Change-Id: I0500f24b65377360d0c74ea390b476e1b879708a
Reviewed-on: https://chromium-review.googlesource.com/1036730
Commit-Queue: Sean Topping <seantopping@chromium.org>
Reviewed-by: Stephen Lanham <slan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557736}