Applying our style guide:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#have-good-hygiene-when-using-temporary-directories

Add more web tests;use blacklist instead of whitelist

The Material Dark Theme spec has been updated (or soon will be) to clarify that the elevation overlay that is applied to surface colors to indicate elevation should be based off of the colorScheme.onSurface color and not white. This commit implements this change.

Reland "AOT support for Linux Desktop I: switch Linux builds to assemble (#41612)" (#42030)" (#42038)

This reverts commit 142a8630.

git@github.com:flutter/engine.git/compare/7d90779bb66f...1d62160fdb2f

git log 7d90779bb66f..1d62160fdb2f --no-merges --oneline
2019-10-04 iska.kaushik@gmail.com Prettify all CMX files (flutter/engine#12800)
2019-10-04 garyq@google.com Restart all modern Samsung keyboard IMM (flutter/engine#12780)
2019-10-04 dnfield@google.com Reland fuchsia build improvements (flutter/engine#12795)
2019-10-04 50856934+nturgut@users.noreply.github.com Fixing selection issues in Firefox (flutter/engine#12793)
2019-10-04 chinmaygarde@google.com Disable EmbedderTest::CanLaunchAndShutdownMultipleTimes. (flutter/engine#12799)
2019-10-04 iska.kaushik@gmail.com [flutter_runner] Update the cmx files to include TZ support (flutter/engine#12798)
2019-10-04 skia-flutter-autoroll@skia.org Roll src/third_party/skia fbdf48ecb204..95edac1c9a4a (1 commits) (flutter/engine#12790)


If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC liyuqian@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/+/master/autoroll/README.md

* Minor clean-up in terminal.dart

* Don't wrap text in tests (otherwise we'll be sensitive to the terminal width).

* remove prints

* Remove the setUpAll() to see if that changes the error message.

This reverts commit 3024053c.

Restructure ProjectFileInvalidator.findInvalidated a bit

I plan to modify `ProjectFileInvalidator.findInvalidated` to allow
it to use `FileStat.stat` instead of `FileStat.statSync`.
Restructure `findInvalidated` a bit so that `FileStat.statSync` is
called in only one place.

Note that this change now always counts the `.packages` file as one
of the files scanned, even if it does not exist.  I think that this
is okay since it more accurately reflects the number of times that we
hit the filesystem with `stat()`, and it is consistent with how other
files are counted.

git@github.com:flutter/engine.git/compare/759d3dba259b...7d90779bb66f

git log 759d3dba259b..7d90779bb66f --no-merges --oneline
2019-10-04 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/linux-amd64 from VkAgX... to by2LL... (flutter/engine#12791)
2019-10-04 bkonyi@google.com Roll src/third_party/dart 28f21d4e99..d6c6d12ebf (3 commits)
2019-10-04 jonahwilliams@google.com Fix bug in package script and add dev_compiler to list of uploaded packages (flutter/engine#12785)
2019-10-04 bkonyi@google.com Roll src/third_party/dart 7a7dcd1ed9..28f21d4e99 (2 commits)
2019-10-04 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/mac-amd64 from wYLiQ... to JyZWz... (flutter/engine#12788)


If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC liyuqian@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/+/master/autoroll/README.md

In preparation for some refactoring that I will be doing to
`ProjectFileInvalidator.findInvalidated`, make its code a bit
clearer:
* Indicate which arguments may be null.
* Don't bother calling `FileStat.statSync` on the `.packages` file
  for the initial load.  This makes the checks for the `.packages`
  file consistent with those for other files.
* Use `DateTime.isAfter()` instead of comparing microseconds
  ourselves.

While I was touching this file, I also removed some unnecessary
comparisons to `false`. (`_ManifestAssetBundle.wasBuiltOnce()` is the
only implementation I can find of `AssetBundle.wasBuiltOnce()`, and
it never returns `null`.)

Bytecode generation will otherwise omit assert code, causing --enable-asserts to have no effect in the VM.

This reverts commit 2b138fd7.

* Generate projects using the new Android embedding

* Add comment about usesNewEmbedding:true

* Feedback

* Rework way to detect new embedding in new apps

759d3dba2 Roll src/third_party/skia 35a60f622c58..fbdf48ecb204 (2 commits) (flutter/engine#12787) (#41965)


git@github.com:flutter/engine.git/compare/ec9d487b0599...759d3dba259b

git log ec9d487b0599..759d3dba259b --no-merges --oneline
2019-10-04 skia-flutter-autoroll@skia.org Roll src/third_party/skia 35a60f622c58..fbdf48ecb204 (2 commits) (flutter/engine#12787)


If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC liyuqian@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/+/master/autoroll/README.md

git@github.com:flutter/engine.git/compare/a0605af402ac...ec9d487b0599

git log a0605af402ac..ec9d487b0599 --no-merges --oneline
2019-10-04 bkonyi@google.com Roll src/third_party/dart b4688e9172..7a7dcd1ed9 (5 commits)


If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC liyuqian@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/+/master/autoroll/README.md

a0605af40 Roll src/third_party/skia d71344590a2f..35a60f622c58 (9 commits) (flutter/engine#12784) (#41958)


git@github.com:flutter/engine.git/compare/9db06370490d...a0605af402ac

git log 9db06370490d..a0605af402ac --no-merges --oneline
2019-10-04 skia-flutter-autoroll@skia.org Roll src/third_party/skia d71344590a2f..35a60f622c58 (9 commits) (flutter/engine#12784)


If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC liyuqian@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/+/master/autoroll/README.md

Revert "replace package:vm_service_client with package:vm_service in the devicelab project (#41646)" (#41960)

git@github.com:flutter/engine.git/compare/2e163b27805b...9db06370490d

git log 2e163b27805b..9db06370490d --no-merges --oneline
2019-10-04 bkonyi@google.com Roll src/third_party/dart 7376167b2a..b4688e9172 (4 commits)


If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC liyuqian@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/+/master/autoroll/README.md

* added questions on Platform / OS Version / Design

* changed following the comments

* removed the host platform question