Chris Bracken 82cd793ee5
Use iOS scale when computing render buffer size (#4171) (#4373)
When checking whether render buffer size has changed, apply the device
scale factor used to convert points to pixels to ensure we're not
needlessly re-allocating render buffer storage.

Adds trace + debug log to make this easier to detect in future.

Originally introduced in 2d530daeca438ca24562d290616c0aec5ab76b88, but
rolled back in 0a6e415b60581ef7934032df20401da1fae9ea9f to test whether
it was responsible for regressions to
flutter_gallery_ios__transition_perf benchmarks:
  * average_frame_build_time_millis
  * missed_frame_build_budget_count

Re-landed in d43d35347594c893687dec7402a525d83f57db10, and reverted in
459f722b86415da01386fe41f37bafa842f11ae8 after it appeared to regress
the above two benchmarks. After recent changes to microtask execution
order which fixed https://github.com/flutter/flutter/issues/9998,
re-introducing this fix results in benchmark improvements to the above
two benchmarks in local testing.
2017-11-20 14:15:26 -08:00
..