[Android] Enable input event stream validation

[Android] Enable input event stream validation

Enable the InputEventStreamValidator by default on Android. Also add
some basic unit tests, and clean up several corner cases that previously
went unnoticed.

BUG=345372
Committed: https://crrev.com/437c0bc77887052385ff97a059d269b957ccf8bf
Cr-Commit-Position: refs/heads/master@{#293437}

[jdduke (slow), 2014-09-04 17:52:01]

Patchset #3 (id:40001) has been deleted

[jdduke (slow), 2014-09-04 17:52:46]

jdduke@chromium.org changed reviewers:
+ tdresser@chromium.org

[jdduke (slow), 2014-09-04 17:52:47]

tdresser@: PTAL, thanks.

[tdresser, 2014-09-04 21:25:01]

LGTM.

https://codereview.chromium.org/537733003/diff/60001/content/common/input/ges...
File content/common/input/gesture_event_stream_validator_unittest.cc (right):

https://codereview.chromium.org/537733003/diff/60001/content/common/input/ges...
content/common/input/gesture_event_stream_validator_unittest.cc:143:
EXPECT_TRUE(validator.Validate(event, &error_msg));
This is one of very few places where you don't check the contents of the
|error_msg|. Might as well make things consistent.

https://codereview.chromium.org/537733003/diff/60001/content/common/input/ges...
content/common/input/gesture_event_stream_validator_unittest.cc:152:
EXPECT_FALSE(validator.Validate(event, &error_msg));
ditto

[jdduke (slow), 2014-09-04 22:48:56]

Hmm, so, turns out we don't actually require a ScrollBegin before a PinchBegin,
at least, the renderer handles it properly and doesn't assume otherwise, and
neither does WebView. 

In practice, the ScrollBegin should always precede it when the gesture is
touch-based, but for synthetic gestures we don't actually require it.  I guess
I'll update the GestureEventStreamValidator. Note that a ScrollBegin should
never happen *between* a PinchBegin and PinchEnd, so we'll keep that validation.

https://codereview.chromium.org/537733003/diff/60001/content/common/input/ges...
File content/common/input/gesture_event_stream_validator_unittest.cc (right):

https://codereview.chromium.org/537733003/diff/60001/content/common/input/ges...
content/common/input/gesture_event_stream_validator_unittest.cc:143:
EXPECT_TRUE(validator.Validate(event, &error_msg));
On 2014/09/04 21:25:00, tdresser wrote:
> This is one of very few places where you don't check the contents of the
> |error_msg|. Might as well make things consistent.

Done.

https://codereview.chromium.org/537733003/diff/60001/content/common/input/ges...
content/common/input/gesture_event_stream_validator_unittest.cc:152:
EXPECT_FALSE(validator.Validate(event, &error_msg));
On 2014/09/04 21:25:00, tdresser wrote:
> ditto

Done.

[jdduke (slow), 2014-09-04 23:05:09]

The CQ bit was checked by jdduke@chromium.org

[commit-bot: I haz the power, 2014-09-04 23:09:42]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jdduke@chromium.org/537733003/80001

[commit-bot: I haz the power, 2014-09-05 04:39:40]

Committed patchset #4 (id:80001) as 995ad8b0b414f70604af0cd9ec22394261a9c3d3

[commit-bot: I haz the power, 2014-09-10 03:36:45]

Patchset 4 (id:??) landed as
https://crrev.com/437c0bc77887052385ff97a059d269b957ccf8bf
Cr-Commit-Position: refs/heads/master@{#293437}