Hopefully this will fix the performance regression in https://github.com/flutter/flutter/pull/13680 but with an easier way to flip the switch.

Small code changes as part of moving the framework SDK forward to a 2.0 dev version.

This cleans up lerp, lerpFrom, lerpTo, and scale methods, and their
documentation.

Fixes https://github.com/flutter/flutter/issues/12377.

This reverts commit dbd3eb67.

Commit above fixed initial problem with frontend_server on Windows, but caused another more explicit problem with gen_snapshot down the line.

* localize a11y tab labels in the TabBar

* break import cycle

* test boilerplate

* fix German translation

* more test boilerplate fixes

* other accounts a11y; show accounts button a11y

* layout with bigger tap areas; all semantics

* internationalize UserAccountsDrawerHeader a11y labels

* better Russian translation

* break import cycle

* address comments

This reverts commit 765191e7.
because the updated packages cause a gradle build problem.

This adds our self-compiled copy of the MinGit executable (built from the flutter/git repo) to the archive when building an archive for Windows.

I also tweaked the internal API for prepare_package.dart so that there's a single entry point to build an archive.

Fixes #12877 by reverting #9472

Adds .vscode/ to the .gitignore rules generated on flutter create.

* support increase and decrease SemanticsActions in time picker

* test roll over

* selected ListTile is selected

* review comment

* analyzer fix

* Gen localization classes intead of a big map

* tighten up the newlines so that std output matches file output

* restore locale sorting

* 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

Prevent header from thinking it can wrap and then overflowing.

Fix default footer string which lost its colon (localized values are fine).

Make the "rows per page" drop-down include at least one value even when the table lacks many items. (Previously it would assert if your table was too short.)

Make the footer scrollable.

Fix some todos and improve some debug output.

Tests for much of the above.

* IconButton is a button, semantically

* fix datepicker test

Applies horizontal safe area insets to the Pesto demo in the Gallery.
This is to support the iPhone X sensor housing notch and other similarly
creative display features when in landscape orientation.

A modern version of 7Zip (7za.exe) is now installed on the bots, this makes use of that.

This replaces the use of ideviceinfo (whose output was then filtered for
device IDs) with an invocation idevice_id -l, which returns the list
directly, one per line.

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 58fe8237 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.

This reverts commit 58fe8237.

Applies horizontal safe area insets to the Contacts demo in the Gallery.
This is to support the iPhone X sensor housing notch and other similarly
creative display features when in landscape orientation.

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.