Moves all remaining calls to tools that are part of the libimobiledevice
suite of tools to the IMobileDevice class. This allows for better
tracking of this dependency, and easier mocking in tests.

None of these is used outside of devices.dart and being public covers up
analysis warnings when they're unused.

All invocations should go via the IMobileDevice class in mac.dart.

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

Use a top-level getter in mac.dart rather than a static instance getter
and a top-level getter in ios_workflow.dart. Makes this code consistent
with how we do context lookups elsewhere.

Extract out IMobileDevice class, move class to idevice_id, ideviceinfo
(and eventually other libimobiledevice tools such as iproxy) behind this
interface.

Add tests for the case where libimobiledevice is not installed, the case
where it returns no devices, and the case where it returns device IDs.

* remove usages of booted

* fix

Eliminates the need for the device/daemon code to get at the iOS/Android
tooling indirectly via Doctor. In tests, we now inject the workflow
objects (or mocks) directly.

- remove unused collector parameter
- clarify a comment
- inline _currentPackageTestDir

This code is unused in any test. In upcoming changes that migrate to
Xcode instruments based device listing, we'll mock out the instruments
output separately.

package:test does not allow main() methods to have required
arguments - changing to an optional positional arguments list
fixes this.

* started copying stuff into cupertino page route

* extracted from material page route. Ready for testing

* works with button and gesture

* tests and docs

* review notes

* review notes

* upload master and alpha docs to different hosts

* include robots.txt when master

https://github.com/flutter/flutter/issues/10688

* Benchmark for semantic overhead during transitions

* review comments

* [accessibility] Announce index if tab in tab bar

* added TODO

https://github.com/flutter/flutter/issues/10688

* Prefix and Suffix support for TextFields

* Adding Tests

* Removing spurious newline.

* Fixing a small problem with the test

* Review Changes

See https://github.com/flutter/flutter/issues/8986

And add comments explaining why.

Currently this just prints the observatory URL as a JSON event.
Refactored the code to make this fit in.