https://skia.googlesource.com/skia.git/+log/7737a5bd2510..5567a6091ceb

2020-10-27 brianosman@google.com Guard traversal of certain kinds of mid-optimization IfStatement
2020-10-27 johnstiles@google.com Pass function arguments using SkSpan instead of count + ptr.
2020-10-27 egdaniel@google.com Add uma histogram tracking for the number of submit render passes.
2020-10-27 johnstiles@google.com Prototype helper functions from FP files before use.
2020-10-27 johnstiles@google.com Mangle function names as a separate step before emitting func-bodies.
2020-10-27 mtklein@google.com remove absl experiment
2020-10-27 mtklein@google.com use ieee divide
2020-10-27 ethannicholas@google.com Made IRNode smaller

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC jcgregorio@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

This partially fixes flutter/engine + dart-lang/sdk head-head build and will allow auto roller to work again.

Adds a package config file to the const finder test fixtures to unblock the null safety flag removal change.

Otherwise these fixtures get opted in to null safety and some constants are missing (presumably because they are invalid).

Related dart-lang/sdk#43872

The Flutter framework now has handling for arrow keys and backspace
in its editable text, so they no longer need to be handled in the
embedding. This not only avoids duplicate work, but improves the
handling of complex unicode (surrogate pairs, grapheme clusters) which
are currently correctly handled in the framework but not the macOS
embedding.

Fixes https://github.com/flutter/flutter/issues/68497

* Add metrics scripts in preparation to move the builder to LUCI.

Bug:
  https://github.com/flutter/flutter/issues/67579

* set -ex to fail scripts inmediately.

* Convert FlutterPlatformViewsController to smart pointer

* have a const reference of platform views controller

* change more stuff to references

Fixes a precision bug was introduced in 784e6d74, which improved the
precision of lerpDouble when the extrema differed significantly in
magnitude.

_lerpInt doesn't have this issue since the extrema are passed as 64-bit
twos-complement values, therefore the difference will always be accurate
so long as it doesn't overflow. This reverts the _lerpInt implementation
to the original a + (b - a) * t, but adds a test to avoid a regression
if anyone is tempted to make it consistent with the others.

This reverts commit cde78c16.