Add pre instrumentation test hooks

Add pre instrumentation test hooks

This is a mechanism to define code to be executed
before tests are run. Updated CommandLineFlags to use
that mechanism

BUG=542859
Committed: https://crrev.com/85081dcf635382688c10dc13e6f8a0bd9a822b5b
Cr-Commit-Position: refs/heads/master@{#353990}

[dgn, 2015-10-07 16:01:23]

dgn@chromium.org changed reviewers:
+ aberent@chromium.org

[dgn, 2015-10-07 16:01:23]

PTAL, the other cl (https://codereview.chromium.org/1387633002) now depends on
this one.

[dgn, 2015-10-09 22:25:46]

The CQ bit was checked by dgn@chromium.org

[dgn, 2015-10-09 22:25:51]

The CQ bit was unchecked by dgn@chromium.org

[dgn, 2015-10-09 22:27:04]

dgn@chromium.org changed reviewers:
+ yfriedman@chromium.org

[dgn, 2015-10-09 22:27:04]

PTAL. I am adding a mechanism to register test hooks from components not
available in base. It is to support https://codereview.chromium.org/1387633002

[aberent, 2015-10-12 12:39:30]

lgtm

[dgn, 2015-10-13 21:31:41]

Friendly ping http://imgur.com/8Qyip1D

[Yaron, 2015-10-13 21:42:41]

lgtm

Sorry for delay

https://codereview.chromium.org/1386353004/diff/1/base/test/android/javatests...
File
base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java
(right):

https://codereview.chromium.org/1386353004/diff/1/base/test/android/javatests...
base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java:68:
result.addPreTestHook(CommandLineFlags.getRegistrationHook());
This seems a little weird to me - the base test fixture reaching into
CommandLineFlags. That said, it doesn't seem any worse than TestResult having
the dependency and is better in that it's more general

[dgn, 2015-10-14 08:29:52]

Thanks!

https://codereview.chromium.org/1386353004/diff/1/base/test/android/javatests...
File
base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java
(right):

https://codereview.chromium.org/1386353004/diff/1/base/test/android/javatests...
base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java:68:
result.addPreTestHook(CommandLineFlags.getRegistrationHook());
On 2015/10/13 21:42:41, Yaron wrote:
> This seems a little weird to me - the base test fixture reaching into
> CommandLineFlags. That said, it doesn't seem any worse than TestResult having
> the dependency and is better in that it's more general

Since we have TestRunners for the different layers (Base, Chrome, WebView soon),
I considered that the test runner for a given layer registers stuff that makes
sense for that layer.

I could have experimented with modifying the test cases instead, I don't know if
#setUp() reliably happens early enough... The fact that we can override it very
easily in any single test doesn't feel that nice too. I think test cases by
themselves should be as small as possible.

[dgn, 2015-10-14 08:30:00]

The CQ bit was checked by dgn@chromium.org

[commit-bot: I haz the power, 2015-10-14 08:30:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1386353004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1386353004/1

[commit-bot: I haz the power, 2015-10-14 10:21:52]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-14 10:22:37]

Patchset 1 (id:??) landed as
https://crrev.com/85081dcf635382688c10dc13e6f8a0bd9a822b5b
Cr-Commit-Position: refs/heads/master@{#353990}