This patch supports basic filtering of log lines from physical iOS
devices, similar to existing functionality for iOS simulator logging.

This patch also suppresses the following two log messages which are
emitted at app startup on iOS 10.3 devices:
  libMobileGestalt MobileGestaltSupport.m:153: pid 123 (Runner) does not have sandbox access for frZQaeyWLUvLjeuEK43hmg and IS NOT appropriately entitled
  libMobileGestalt MobileGestalt.c:550: no access to InverseDeviceID (see <rdar://problem/11744455>)

This reverts commit 8d07d3f6.

* Bump Dart SDK to 1.25.0-dev.9.0

* add link to sdk bug

In some cases, we've seen interactions between Instruments and the iOS
simulator that cause hung instruments and DTServiceHub processes. If
enough instances pile up, the host machine eventually becomes
unresponsive.

Until the underlying issue is resolved, manually kill any orphaned
instances (where the parent process has died and PPID is 1) before
launching another instruments run.

* Disable cocoapods stats

* Add a comment for code readers

* fix new test

* start

* with create

* refactor cocoapod code, add tests

* fix tests

* throw when cocoapod missing

* obj-c projects don’t use use_framework!

* minor tweaks to the output for flutter_tools

* update test expectations

* Output verbose cocoapods output when pod install has an error or if flutter build/run is in -v

* remove repeated stdout

* Guess sign with the first certificate when multiple are available in machine mode

* review

In the case where the CocoaPods 'pod install' step fails, emit its
stdout to provide any potentially-useful error messages to the user.

Previously, xcodeMajorVersion and xcodeMinorVersion returned null unless
xcodeVersionSatisfactory had been called first. We now compute them on
demand, and cache the resultant values.

1. Run all Xcode tool invocations through ProcessManager, which allows
us to mock out failures, etc. for tests.

2. Add said tests.

This reverts commit 3e265e9e.

Rather than pre-compute Xcode install path, version, and EULA status,
compute and cache on demand.

This reverts commit bb8e2a7c.

Triggers a doctor failure on the Mac chromebots.

Rather than pre-compute Xcode install path, version, and EULA status,
compute and cache on demand.

This allows us to take advantage of improved command-line tooling (e.g.,
improvements in device listing in Instruments). Now that the engine is
built with Xcode 8 and the framework is tested against Xcode 8, this
reduces the set of configurations we need to support to allow us to
focus on the supported ones: Xcode 8 and Xcode 9.

This print statement provides no value to the user.

This libimobiledevice tool is no longer used anywhere in the flutter_tools codebase.

This reverts commit b2909a24.

This resubmits the following patches:

1. Use Xcode instruments to list devices (#10801)
Eliminates the dependency on idevice_id from libimobiledevice. Instead,
uses Xcode built-in functionality.

2. Make device discovery asynchronous (#10803)
Migrates DeviceDiscovery.devices and all device-specific lookup to be
asynchronous.

* Revert "Make device discovery asynchronous (#10803)"
This reverts commit 972be9c8.

* Revert "Use Xcode instruments to list devices (#10801)"
This reverts commit 37bb5f13.

This is to resolve a failure that looks related to a bad install of Xcode 8.0
on our build bots and should be reinstated when the infra issue is diagnosed
and resolved.

Instruments worked well when this was originally landed, and on the
following commit, but started failing two commits after this originally
landed. Manual invocation of instruments on the build host currently
results in:

```
dyld: Library not loaded: @rpath/InstrumentsAnalysisCore.framework/Versions/A/InstrumentsAnalysisCore
  Referenced from: /Applications/Xcode8.0.app/Contents/Developer/usr/bin/instruments
  Reason: image not found
Abort trap: 6
```

It appears the /Applications/Xcode8.0.app/Contents/Applications
directory (which contains Instruments) is missing on the host.

Migrates DeviceDiscovery.devices and all device-specific lookup to be
asynchronous.

Eliminates the dependency on idevice_id from libimobiledevice. Instead,
uses Xcode built-in functionality.

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.

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.

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.