In order to reduce search startup time from the omnibox, create a spare renderer when it is likely that a web search will be done. This will pipeline renderer process creation for search queries when there is a service worker.
The idea is to use a factory all the time in RenderProcessHostImpl::GetProcessHostForSiteInstance instead of just for testing as is currently done. This factory will hold a single RenderProcessHost which can be created on demand. When called with a matching browser_context and storage_partition, it will return the host if it exists. If the context and partition don't match it will be destroyed.
We discussed starting a service worker bound to the domain of the default search provider, which would also pipeline the service worker initialization. However, currently this would also mean that a new renderer process will be created for the navigation. If the service worker is started with the navigation (as it would be with the spare renderer idea), then they will live in the same process when appropriate. Thus we avoid using two processes at the expense of not saving service worker initialization time.
Comment 1 by creis@chromium.org
, Jun 14 2017Components: Blink>ServiceWorker UI>Browser>Navigation Internals>Core