* Update packages

* Change test for isFile

This reverts commit 30f33d6c.

Fixes https://github.com/flutter/flutter/issues/26544

* move flutter_assets to App.framework

* Roll engine to 05fee4eeee0ff6b219b1fcc394371e5f6963cc46

05fee4eee Update default flutter_assets path for iOS embedding (flutter/engine#7518)
02205db01 Roll src/third_party/skia 5d052dac3ac1..02738a86e5fd (4 commits) (flutter/engine#7541)
af907c074 Roll src/third_party/skia 5c7a3ac0e214..5d052dac3ac1 (7 commits) (flutter/engine#7540)
dde286673 IWYU to get SkFontMetrics (flutter/engine#7539)

* Rev Android Platform to 28 for bots

* push all to 28

* include platform tools update

This reverts commit d8db70af.

* move flutter_assets to App.framework

* remove flutter_assets references from all pbxproj files checked in

This adds some functions to the interface for RawKeyEventData and all subclasses that allow the recipient of an event to determine which modifier keys are currently being pressed without needing to know the specific modifier bitmasks for the platform.

Also adds constants for the modifier bitmasks for each platform, for completeness (and because I needed them anyhow to implement the above).

Added tests for the RawKeyEventData subclasses, and modified the raw_keyboard manual test app to show modifier keys being pressed. I also separated the different platform-specific subclasses into separate files.

Fixes #26155.

This reverts commit 71e9bd6f.

This reverts commit 76a1abd4.

This reverts commit 949cfcf1.

* Use Xcode build configurations to drive Flutter build mode

* Proper check wrt local_engine, print error if profile mode misisng

* Remove unused code, update tests, fix template problem, update warning

* fix up warning

* add explanatory dev comment

* fix whitespace

* missing words, change lambda arrow to function body

* error indentation

* Test early exits for xcode_backend.sh

* only on macOS, use right test

* Update error messages

* case insensitive compare for build config

* Update gallery podfile

* update projects to add profile configuration

* make compatible with flavors

* add missing plist files

* add FLUTTER_FRAMEWORK_DIR back, set swift version for profile, tell Podfile about profile

* Revert "Update templates (#23698)"

This reverts commit 5b0de6d6.

* Revert "Verify that date/number translations exist for all supported languages (#23692)"

This reverts commit 3449edf2.

* Revert "Reland Xcode backend refactor (#23574)"

This reverts commit 7270f284.

* Use Xcode build configurations to drive Flutter build mode

* Proper check wrt local_engine, print error if profile mode misisng

* Remove unused code, update tests, fix template problem, update warning

* fix up warning

* add explanatory dev comment

* fix whitespace

* missing words, change lambda arrow to function body

* error indentation

* Test early exits for xcode_backend.sh

* only on macOS, use right test

* Update error messages

* case insensitive compare for build config

* Update gallery podfile

* update projects to add profile configuration

* make compatible with flavors

* add missing plist files

This reverts commit 751c083f.

Our buildbots need to be upgraded to a newer version of the Android SDK.

Adds a Fuchsia compatibility function that allows for connecting to a
specific Isolate by name when running Flutter Driver on a Fuchsia
device.  This will check over multiple Dart VM's in an attempt to find
an Isolate by its name.

This reverts commit 3c56e6c7.

It breaks the AOT build.

* first pass

* revert WidgetsBindingObserver

* disable prefer_mixin

* docs and more mixins

* newer engine; binding fixes

* upgrade dependencies

* fix test binding

* remove whitespace

* remove the obsolete `enableSuperMixins: true`

* upgrade dartdoc to 0.22.0

* temporarily use git version of dartdoc

* fix pub global activate syntax

* use dartdoc 0.23.0

* Refactor of cupertino/material/widgets app

* update docs 

* Update tests for const

This reverts commit 61cf946b.

* Make CupertinoApp and MaterialApp both use WidgetsApp for Navigator

* Make CupertinoApp and MaterialApp const constructors

* Make WidgetsApp routes aware

* Update tests

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Reland "Roll engine to version b148e628ec86b3a9a0382e0bcfae73f0390a8232 (#20427)"

This is a re-land with downgraded `package:flutter_gallery_assets`
version.

* Downgrade package:flutter_gallery_assets to 0.1.4

* Change engine.version to 81baff97c29bb08cbf8453a3f9042c5813f84ad3 (which contains an additional fix)

* Change engine.version to e3687f70c7ece72000b32ee1b3c02755ba5361ac (since mac tarballs are corrupted on earlier commit)

Reason for revert: The package:flutter_gallery_assets has removed some images which are required for the examples/flutter_gallery, so the gallery build is failing (only discovered after landing, since gallery doesn't seem to get built during github PR presubmit checks)

This CL

  * rolls `engine.version` to flutter/engine@b148e628 (which includes dart sdk 2.1.0-dev)
  * rolls `goldens.version` to flutter/goldens@6c45fafdf (which includes updates due to skia changes in engine)
  * changes `platform.dill` to `platform_strong.dill` in various places due to flutter/engine@a84b210b
  * adds explicit `environment: sdk: ">=2.0.0-dev.68 < 3.0.0"` constraints to `pubspec.yaml` and `pubspec.yaml.tmpl` files (since pub defaults to `<2.0.0` if omitted) 
  * upgrades to newer versions of various 3rd party packages (to ensure transitive dependencies have `<3.0.0` sdk constraint)

* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test