* Revert "Enable line join styles and miter limit. (#3777)"

This reverts commit 5403f65b.

* Revert "Revert "Update switches to use StringView." (#3784)"

This reverts commit 80f039ff.

* Revert "Initial integration of libtxt with Flutter alongside Blink. (#3771)"

This reverts commit c548c65b.

* Add support for join types and miter limits.

* Fix miter limit data type.

* Adding some clearer documentation to painting.dart

* Clarifying more documentation.

* Code review changes

* Fixed debug printing of stroke width and miter limit

* Adding missing periods at the ends of sentences.

* Revert "Initial integration of libtxt with Flutter alongside Blink. (#3771)"

This reverts commit c548c65b.

* Revert "Call Selection.removeSelection if the framework has cleared the selection (#3782)"

This reverts commit e5b79ba6.

* Revert "Update switches to use StringView. (#3781)"

This reverts commit 07d4357b.

Fixes https://github.com/flutter/flutter/issues/10748

See https://fuchsia-review.googlesource.com/#/c/31931/.

See https://github.com/flutter/flutter/issues/10701

* Roll Dart dependency

* Update license file

* Removed 'pub get' from the instructions

According to Hixie, 'pub get' is abstracted into flutter packages upgrade, and so there shouldn't be a need to run pub get directly.

* Removed pub get lines entirely.

This reverts commit ffe8181f.

In particular, this avoids some unnecessary calls to InputMethodManager.restartInput
that caused noticeable lag when moving the cursor.

Fixes https://github.com/flutter/flutter/issues/9928

Both the following, which we also support, are deprecated in UIKit:

* `application:handleOpenURL:`
* `application:openURL:sourceApplication:annotation:`

Expose performActionForShortcutItem call to all registered plugins so we can handle quick actions (#3763)

* Expose performActionForShortcutItem call to all registered plugins so we can handle quick actions

* Should return BOOL not void

* clang-formatted

* Adding SemanticsFlag.isSelected

* typo

* Run Flutter on iOS and Android with color correct Skia (#3716)

***Turns on color correct rendering for Android and iOS
***Communicates dst color space to raster cache
***Turns on color space aware image decoding

Test:
***color_testing_demo on Pixel XL
***flutter_gallery on iPad Mini and iPad Pro (haven't figured out how to run manual_tests on iOS)

TODO:
I needed to split up this CL somewhere. These are follow-up tasks.
***Make desktop backends color correct
***Make debugging tools (ex: encoding frames to png) preserve color space
***Investigate using UIKit API to allow iOS to fine tune color space of rendered content

This creates a `FlutterFragmentActivity` class that extends
the Android v4 Support librray's `FragmentActivity` class.
However, we intentionally do not bundle the support library
with our engine, so apps that wish to use this class are
responsible for including the support library .jar file in
their runtime deps when creating the final app.

flutter/flutter#10072

* Roll Dart dependency in Flutter engine to pick up assert in constructor's initializers support

* Missing comma

* Use correct revision

* Rev up, update license

* Update to sky/pacakges/sky_engine/LICENSE

* Roll to updated ver with license text fixed

* Update license file

Use the value specified in build/config/ios/ios_sdk.gni in the buildroot
repo.

Updates buildroot to 4d1c1fd7103d6daba559e456a6a68e4385bb28f1

This factors the functionality that was in `FlutterActivity`
to live in `FlutterActivityDelegate`. This will allow the creation of a
`FlutterFragmentActivity` that has the same core functionality, which in
turn unlocks certain Android plugins that choose to require the v4
support library (like Google Sign-In).

https://github.com/flutter/flutter/issues/10072

ios_tools exists to provide find_xcode.py, which is used only on the Mac
Engine bot to select the correct version of Xcode to build with.

This adds a dependency on the Chromium iOS build tooling to support
deterministic selection of Xcode version on the Mac_Engine build bots.

This patch adds support for the new way of exposing services from applications.

* Retain the parent of a SemanticsObject

This fixes the last known crash in iOS accessibility.

* rework memory management

* review comments

* Fix pixel rounding error in the picture layer by first ensuring that
  the texture for the image is at least as big as the next integer size
  along each dimension and using kStrict_SrcRectConstraint while
  drawing the same image. We already select the source subset by
  looking at the cull rect of the picture.
* Decompose the transformation matrix into a series of operations that
  generated the same to calculate the scale at which to rasterize the
  picture. This make the rasterization scale resilient to
  transformations that introduce a perspective component to the
  resultant matrix.
* The scale in the decomposed matrix is now part of the key in the
  cache.
* Raster cache images that could never be rasterized were still taking
  part in the cache. Now, those entries are rejected early on. This
  leads to the sweep after the frame iterating over fewer items.
* Added a unit test target.