* Use Java bundled with Android Studio for gradle

* review comments

Go through all packages brought in by pub, and write the name and path of every one that is a flutter plugin into .flutter-plugins.

In android/settings.gradle and ios/Podfile, read in .flutter-plugins, if that file exists. The Android / iOS code from the plugins is automatically added as dependencies of the native code of the app.

* Add start-up test for flutter_view sample

* add reportMetrics flag to startup test

* rewording in manifest.yaml

**THIS IS A BREAKING CHANGE.** See below for migration steps for
existing projects.

Previously, Flutter app code was built as a raw dylib on iOS.  Dynamic
libraries outside of a framework bundle are not supported on iOS, except
for the system Swift libraries provided by Xcode.

See:
https://developer.apple.com/library/content/technotes/tn2435/_index.html#//apple_ref/doc/uid/DTS40017543-CH1-TROUBLESHOOTING_BUNDLE_ERRORS-EMBEDDED__DYLIB_FILES

* Migrates Xcode build from app.dylib to App.framework
* Migrates flutter create template
* Migrates example projects

Migration steps for existing projects
=====================================

The following steps should be taken from the root of your Flutter
project:

1. Edit `ios/.gitignore`: add `/Flutter/App.framework` on a new line.
2. In the Xcode project navigator, remove `app.dylib` from the Flutter
   folder. Delete this file from the `ios/Flutter` directory in your project.
3. Run a build to generate `ios/Flutter/App.framework`. From the command
   line, run `flutter build ios`. If you have not configured app signing
   in Xcode, an alternative method is to open the simulator, then run
   `flutter run -d iP`.
4. In the Xcode project navigator, select the `Runner` project. In the
   project settings that are displayed in the main view, ensure that the
   `Runner` target is selected. You can verify this by exposing the
   sidebar using the [| ] icon in the upper-left corner of the main
   view.
5. Select the *General* tab in the project settings. Under the
   *Embedded Binaries* section, click '+' to add `App.framework`. In the
   sheet that drops down, click the *Add Other...* button. Navigate to
   the `ios/Flutter` directory and select `App.framework`. Click *Open*.
   In the sheet that drops down, select *Create folder references*, then
   click *Finish*.
6. In the project settings, verify that `App.framework` has been added to the
   *Embedded Binaries* and *Linked Frameworks and Libraries* lists.
7. In the Xcode project navigator, drag `App.framework` under the
   Flutter folder.
8. In the Xcode project navigator, select `Flutter` then from the
   *File* menu, select *Add Files to "Runner"...*. Navigate to the
   `ios/Flutter` directory, select `AppFrameworkInfo.plist` and click
   the *Add* button.
9. From the command line, in your project directory, run
   `flutter build clean`, then `flutter run`.

At this point your project should be fully migrated.

* Teach flutter_tools to populate PUB_ENVIRONMENT

Will allow telemetry reporting on pub.dartlang.org once
flutter moves to 1.23.0-dev.10.0

* review changes

* Improvements to CircleAvatar default color (for codelab)

* use a transparent white instead of a solid one

* Fix analyzer errors

* fix tests

* Print error message if a package is skipped during DevFS sync.

* review comments

* more review comments

* fix test

* Remove unnecessary Android SDK checks.

* Remove unused accessors, skip replay test.

* Refactor platform_services sample

* removed exception

* Revert "use color.shadeXxx instead of color[Xxx] (#8932)"

This reverts commit 578ca0a2.

* Revert "add missing const keyword (#8931)"

This reverts commit fac2fac1.

* Revert "Make min/max fling velocity and min fling distance ScrollPhysics properties (#8928)"

This reverts commit dac80aac.

* Revert "Defer to operating system for whichAll (#8921)"

This reverts commit 14933de9.

* Revert "Update gradle wrapper and build-tools version for flutter create. (#8914)"

This reverts commit deb71cc6.

* use color.shadeXxx instead of color[Xxx]

* remove calls to .shade500 on MaterialColor

* remove calls to .shade200 on MaterialAccentColor

* fix test

The old `whichAll` implementation was not considering different extensions for executables on Windows. By defering to OS-built-in tools we avoid implementing it.

Fixes #8882.

* Update gradle wrapper and build-tools version.

Tested manually by "flutter create" with Idea "flutter run" and from android studio "run" android app.

* Update com.android.tools.build to 2.3.0

This patch prepares us to remove InputValue in favor of TextEditingValue.

* Avoid downloading artifacts twice

* Don't update cache before `flutter upgrade` is executed (`flutter upgrade` might bump the engine version)
* Don't update cache twice during `flutter precache`

Fixes #8249.

* add test

Fixes #8235

Fixes #8794

Fixes #8519

The latter is the proper spelling.

Fixes #8883

We keep breaking --watch because we don't test it.

Fixes #7520

Fixes #4017

Previously they tried to compute an integer target end index, but
integers can't represent infinity. Now we use null to represent
infinity.

Also, fix some similar issues with grids.

Fixes #8398