Improve hot reload test mode

Improve hot reload test mode

- [x] Start reloading even earlier.
- [x] Keep the value of FLAG_reload_every per-isolate (so spawned isolates reload eagerly too).
- [x] Adjust the reload every back off curve to be linear in the beginning.
- [x] Cap the reload every threshold at 1,000,000
- [x] Test status file updates.
- [x] Stop disabling the background compiler / OSR when running tests.
- [x] Skip multi tests with compilation errors when reloading.

BUG=
R=rmacnak@google.com

Committed: https://github.com/dart-lang/sdk/commit/ef71bc1834d1594349c34401b5a97fe071139bef

[Cutch, 2016-07-08 17:51:05]

Description was changed from

==========
Improve hot reload test mode

BUG=
==========

to

==========
Improve hot reload test mode

- [x] Start reloading even earlier.
- [x] Keep the value of FLAG_reload_every per-isolate (so spawned isolates
reload eagerly too).
- [x] Adjust the reload every back off curve to be linear in the beginning.
- [x] Cap the reload every threshold at 1,000,000
- [x] Test status file updates.
- [x] Stop disabling the background compiler / OSR when running tests.
- [x] Skip multi tests with compilation errors when reloading.

BUG=
==========

[Cutch, 2016-07-08 17:51:05]

johnmccutchan@google.com changed reviewers:
+ rmacnak@google.com

[rmacnak, 2016-07-11 19:18:22]

lgtm

https://chromiumcodereview.appspot.com/2133823002/diff/1/tools/testing/dart/m...
File tools/testing/dart/multitest.dart (right):

https://chromiumcodereview.appspot.com/2133823002/diff/1/tools/testing/dart/m...
tools/testing/dart/multitest.dart:282: // Skip multi tests with compilation
errors when hot reloading.
// Running a test that expects a compilation error with hot reloading is
redundant with a regular run of the test.

[Cutch, 2016-07-11 19:29:19]

Description was changed from

==========
Improve hot reload test mode

- [x] Start reloading even earlier.
- [x] Keep the value of FLAG_reload_every per-isolate (so spawned isolates
reload eagerly too).
- [x] Adjust the reload every back off curve to be linear in the beginning.
- [x] Cap the reload every threshold at 1,000,000
- [x] Test status file updates.
- [x] Stop disabling the background compiler / OSR when running tests.
- [x] Skip multi tests with compilation errors when reloading.

BUG=
==========

to

==========
Improve hot reload test mode

- [x] Start reloading even earlier.
- [x] Keep the value of FLAG_reload_every per-isolate (so spawned isolates
reload eagerly too).
- [x] Adjust the reload every back off curve to be linear in the beginning.
- [x] Cap the reload every threshold at 1,000,000
- [x] Test status file updates.
- [x] Stop disabling the background compiler / OSR when running tests.
- [x] Skip multi tests with compilation errors when reloading.

BUG=
R=rmacnak@google.com

Committed:
https://github.com/dart-lang/sdk/commit/ef71bc1834d1594349c34401b5a97fe071139bef
==========

[Cutch, 2016-07-11 19:29:21]

Committed patchset #2 (id:20001) manually as
ef71bc1834d1594349c34401b5a97fe071139bef (presubmit successful).

[Cutch, 2016-07-11 19:29:55]

https://chromiumcodereview.appspot.com/2133823002/diff/1/tools/testing/dart/m...
File tools/testing/dart/multitest.dart (right):

https://chromiumcodereview.appspot.com/2133823002/diff/1/tools/testing/dart/m...
tools/testing/dart/multitest.dart:282: // Skip multi tests with compilation
errors when hot reloading.
On 2016/07/11 19:18:22, rmacnak wrote:
> // Running a test that expects a compilation error with hot reloading is
> redundant with a regular run of the test.

Done.