Apple encodes syslog entries using a 7-bit encoding where input UTF-8 bytes
are encoded as follows:
1. 0x00 to 0x19: non-printing range. Some ignored, some encoded as <...>.
2. 0x20 to 0x7f: as-is, with the exception of 0x5c (backslash).
3. 0x5c (backslash): octal representation \134.
4. 0x80 to 0x9f: \M^x (using control-character notation for range 0x00 to 0x40).
5. 0xa0: octal representation \240.
6. 0xa1 to 0xf7: \M-x (where x is the input byte stripped of its high-order bit).
7. 0xf8 to 0xff: unused in 4-byte UTF-8.

As there doesn't appear to be a system tool to decode these strings, we
implement here in Dart. If we're unable to decode a string (e.g.
decoding results in an invalid UTF-8 string), we fall back to emitting
the log line as-is.

* it's fixed

* Add test for simulator log reader

* Revert "Revert "Enable developers to run pod from terminal directly and skip pod install if possible. (#13374)" (#13770)"

This reverts commit 0759043e.

* some nits on cocoapods code

* put back the FLUTTER_FRAMEWORK_DIR env variable

Revert "Enable developers to run pod from terminal directly and skip pod install if possible. (#13374)" (#13770)

This reverts commit c6a17525.

Avoids running pod install if .flutter-plugins and its flutter framework pod dependency didn't change

* Change async stubbing to use thenAnswer.

Mockito now prohibits calling thenReturn with Futures and Streams. dart-lang/mockito#79

* Update all Mockito deps to 3.0.0.

* Revert "Update all Mockito deps to 3.0.0."

This reverts commit e8ab9d37c33d3d7fe384abde64ea5b4d72623c75.

I did not correctly update the mockito dep, and there's no easy way to update to 3.0 alpha right now.

* Change thenAnswer((_) => to thenAnswer((invocation) =>

* Add Invocation type to thenAnswer lambdas

We now require Xcode 9.0, which ships with the iOS 11 SDK, for iOS
builds. This change does not affect the minimum supported iOS deployment
target, which remains iOS 8.

The iOS 11 SDK adds support for safe area insets, which model the status
bar, iPhone X home indicator, and symmetric horizontal insets to avoid
the iPhone X sensor housing when in landscape mode.

This re-lands flutter/flutter#13608 now that the devicelab Macs have
been updated to Xcode 9.

Our devicelab machines have not yet been upgraded to Xcode 9. Once this
has been done, I'll re-land this.

This reverts commit 0fac5f01.

We now require Xcode 9.0, which ships with the iOS 11 SDK, for iOS
builds. This change does not affect the minimum supported iOS deployment
target, which remains iOS 8.

The iOS 11 SDK adds support for safe area insets, which model the status
bar, iPhone X home indicator, and symmetric horizontal insets to avoid
the iPhone X sensor housing when in landscape mode.

Add support for IOS_SIMULATOR_HOME environment variable in IOSSimulator.logFilePath

flutter_tools can be run on environments where the user's HOME directory
is not the root of the iOS simulators' configs. This change adds support
for such environments by allowing the caller to set the simulator root
directory via an environment variable.

Differentiate between 'not installed' and 'not working' and emit a more
targeted message.

1. Migrate simulator device log tailing to os_log toolchain
2. When the log tag (component) is available (iOS 11/Xcode 9), filter to
   the set of log lines with tag 'Flutter'.

As of iOS 11 / Xcode 9, Flutter engine logs are no longer recorded in the
simulator's syslog file, which we previously read using tail -f. Instead
they're now accessible through Apple's new macOS/iOS os_log facility,
via /usr/bin/log, which supports a relatively flexible query language.

When run in non-interactive mode, /usr/bin/log buffers its output in 4k
chunks, which is significantly smaller than what's emitted up to the
point where the observatory/diagnostics port information is logged. As a
workaround we force it to run in interactive mode via the script tool.

This was introduced to suppress libMobileGestalt noise originating from
libsystem_asl.dylib. Commit 39680ebf
suppresses all application log messages not originating from the
app/engine iteself on iOS 10 and above. Since the log message in
question is only emitted on devices running iOS >= 10.3.0, this
blacklist no longer necessary.

On iOS 10 and above, suppress engine log messages from system components
other than Flutter. This eliminates a large amount of keyboard/plugin
related noise during edit-refresh development.

ios-deploy 1.9.2 includes fixes for a common source of Xcode breakage
(flutter/flutter#4326) with Xcode 8.3.3 + iOS 10.3.3, and is required to
to support Xcode 9 (flutter/flutter#11875).

This patch migrates iOS device listing from using Xcode instruments to
using the libimobiledevice tools idevice_id and ideviceinfo.

ideviceinfo was previously incompatible with iOS 11 physical devices;
this has now been fixed.

In 37bb5f13 flutter_tools migrated from
libimobiledevice-based device listing on iOS to using Xcode instruments
to work around the lack of support for iOS 11. Using instruments entails
several downsides, including a significantly higher performance hit, and
leaking hung DTServiceHub processes in certain cases when a simulator is
running, necessitating workarounds in which we watched for, and cleaned
up leaked DTServiceHub processes. This patch returns reverts the move to
instruments now that it's no longer necessary.

* upgrade to linter-0.1.35

* re-enable lint prefer_const_constructors

* address review comments

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.

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!

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

* review

And fix a typo in a test description.

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

Also, correct an existing test description.

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 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.