BackingStore objects can be reused in DrawingAreaProxyImpl::didUpdateBackingStoreState as per a FIXME: comment. This is likely to be more efficient.
Created attachment 93604 [details] Patch to reuse backing stores and reduce timeout to 2 seconds
Comment on attachment 93604 [details] Patch to reuse backing stores and reduce timeout to 2 seconds View in context: https://bugs.webkit.org/attachment.cgi?id=93604&action=review r=me > Source/WebKit2/UIProcess/DrawingAreaProxyImpl.cpp:212 > + // If we have a backing store the right size, reuse it. "backing store that is the right size" would make for a more grammatically correct comment.
Committed r86524: <http://trac.webkit.org/changeset/86524>
Was any (non-memory) performance testing done of the 5 second -> 2 second change? See bug 51262 comment 5 and bug 51262 comment 6 (and other comments, too) for how the 5-second interval was arrived at.
(In reply to comment #4) I did some bench testing looking for white flash problems. This included running with little free memory and a large number of tabs / windows (40-50). I didn't notice any white flashing or unreasonable delays. With instrumentation, I noticed that the number of backing stores would grow as needed.