* Revert "Add pub cache, artifacts, pkgs to Cirrus cache (#20080)"

This reverts commit 07e93b38.

* Revert "Reduce noise on the memory benchmarks (#19630)"

This reverts commit 8eb5cb7d.

This adds:
 - pub's cache to the Cirrus cache. It caches based on the checksums in the pubspec (although pub has things in versioned folders, this'll prevent the cache just getting bigger over time).
 - bin/cache/pkg. I think this only includes sky_engine. It caches based on the engine checksum.
 - bin/cache/artifacts. This includes engine, gradle_wrapper, material_fonts. Also caches based on the engine checksum.

- Check memory usage in release builds, not profile.
- Use multiple runs and average the results.

This will reduce load on macOS community cluster.

//mobile/flutter/tests/app:basic_runner_test_*
during a google3 roll.

The following exception was being thrown

_TypeError: type 'String' is not a subtype of type 'File'

```
8)
<asynchronous suspension>
utter_command.dart:347:18)
<asynchronous suspension>
/flutter_command.dart:282:33)
<asynchronous suspension>
xt.dart:142:29)
<asynchronous suspension>

flutter/engine@6929326 Roll ICU to 62.1 and harfbuzz to 1.8.4

flutter/engine@de5f535 Make FML task runner methods virtual so that FXL adaptors in Fuchsia are possible.
flutter/engine@33b4123 Fix sundry Fuchsia build issues after the tonic/fxl migration.
flutter/engine@03a4e53 Update license script & analyze it on CI
flutter/engine@9f9a564 Change CI badge from travis to cirrus
flutter/engine@a61fae0 Dart SDK roll for 8/1/2018
flutter/engine@97e7c6e Roll src/third_party/skia fd98c2c87164..afea9c32acd9 (1 commits)
flutter/engine@1a35c51 Roll src/third_party/skia f4bf7fc35d83..fd98c2c87164 (1 commits)
flutter/engine@8cb0f6d Roll src/third_party/skia 6cfa29738295..f4bf7fc35d83 (2 commits)
flutter/engine@dcd2956 Initial support for more finely-grained a11y features on Window
flutter/engine@83da727 Roll src/third_party/skia 1935aa3d27cd..6cfa29738295 (7 commits)

This reverts commit 724b9249.

* Dart SDK roll for 8/1/2018

Dart SDK roll and disabling of return warnings as errors.

List of commits included in this roll:

8bad5c7b29 [vm/compiler] Non-speculative X64 long division/remainder.
918cda18c5 Add docs about sourcemap extensions
329e029bd6 Fixes dart-lang/sdk#34035
12326c10e1 Store constructor field initializera when the target is not a field.
50da4b8d92 Skip ShadowInvalidFieldInitializer while resynthesizing constructor initializers.
8810b6ecc7 Translate kernel.Instantiation in constant expressions.
cb7341fceb Initial support for inlining-data in source-maps.
4206131030 Fix tracking of onStep position of arguments to new expression
384b0a9a73 Issue 34038. Fix resynthesizing imports when mixed with exports.
ba7dbcf412 Update the test output processor to produce more useful analysis
4b2ee8e9a5 Improve catch clause recovery
66500de4dc More fixes to the CFE integration tests
3f2251986d CC sra also in changes to compiler files and tests
4734c55882 Report error on unsupported operators
00e3109368 [VM] Adjust flags for creating depfiles
07c462b471 [vm] Refactoring: extract BaseFlowGraphBuilder to a separate file
ff9167ff7b Fix parseDirectives to recognize metadata
079bebb78b [ VM ] Added missing token position for assert statements
174649b9be [gardening] Update status of dissasemble_test on Windows
8c5aca7d4d Remove the Factory interface
3dc201e168 Update ChangeBuilder to not include empty edits (Take 2)
18047b2757 Refactor test.dart by changing class Configuration to TestConfiguration
7373d38a31 Update status for Dart2js minified CSP on Chrome with fast startup
61148eade8 Update mixin-declaration feature specification.
a98feb0f01 [VM interpreter] Fix exception handling. Convert bytecode indices to pc offsets ....
da2ed2fd59 Don't ignore runtime cast failures on Map<K,V>.
3d8ca8e566 [gardening] Increase debug app-jitk timeout
0313f7bd66 [gardening] Update status file for failing test
6c39bc38f3 Clear ShadowX references that are not required after compilation.
05b9bbd2b5 Remove the dart1 version of the analysis server snapshot.
9107399190 Add back in the analysis server training.
9fb6c09015 Store reference/type for invalid types.
21db860271 Remove non-strong dart2js builders from test_matrix.json
2e7b0a13f1 Add support for accessing all of the created contexts
73663ae7c6 Allow void on the RHS of null coalescing expressions
17cb6d95d1 Don't remember TypeEnvironment in resolution results.
72960de5f9 [VM] Fix one more place where bound error allocation happened on BG thread in new space
6ad79ff4bd Update status file for tests passing under CFE
23ba527735 [VM] Ensure to alloate bound errors in old space on BG compiler
fe8052428b Remove CONTENT_MODIFIED from spec/test for getSignature
c4c847a45c Revert "[CQ] Remove pkg-linux-release from the CQ trybots until it is fixed"
beaf05efa3 [vm] When generating JITDUMP also dump IR and attach it as source to code.
24158b773d [vm/compiler] Do not LICM LoadStaticField for uninitialized fields.
68bfaf3ac3 [vm/compiler] Avoid crashes when canonicalizing unreachable AssertAssignable.
5a45b2a62b [infra] Upgrade homebrew dependencies to work on Dart 2
8e287dc037 [VM] Only add direct implementor when reading script snapshots if ....
6e81d74fcc [VM] Optimize generation of type testing stubs in JIT mode.
058510eeab fix #28233, add hint for missing returns to function expressions
4482d13ff7 [vm/compiler] Bug fix in 64-bit MOD (%) operator.

* Try ignore instead of commenting out.

* Also disable this in package analysis options.

This enables using GoldensClient from the flutter driver file for the
embedded Android views test.

flutter_goldens.dart has a transitive dependency on dart:ui so it cannot
be included in non Flutter apps. Splitting it out allows us to use it
from driver tests.

This also removes the visibleForTesting annotation from GoldensClient.

This reverts commit 7a9dd709.

Bug: https://github.com/flutter/flutter/issues/19490

* Drawer fix

* fixed nits

* fixed nits

* fixed nits

* final change

* Drawer fix final

* Skip tests instead of expecting failure, because expected failure = timeout which is slow

Some of these tests are known to fail and were coded to expect it; however because the failure is a timeout it's just dragging out test runs (shortening timeouts will make the tests flakier).

* Make it easier to find skipped tests

* Change SKIP to TODO

I switched to just checking for spaces and tabs, since otherwise it expresses a preference for line endings that I think should be taken care of at the git level (and I think they are).

I also fixed a bug where I was looking for ".yml" instead of "*.yml" files, and clarified an output message.

remove the option to pass in the --no-preview-dart-2 flag to analysis

Enables animated curve diagrams in the documentation, replacing the static images.

Fixes #19617