Find In Page doesn't correctly highlight wrapped text.

Find In Page doesn't correctly highlight wrapped text.

With "white-space: pre-wrap" texts which consist line break,
we get 3 ranges for documentMarker (+ve, +ve) (-ve, +ve) and (-ve, +ve).
So, when we pass -ve offset to SimpleShaper::advance which takes unsigned
value, it converts the -ve offset to very large unsigned value.
Because of this, Font::selectionRectForText "width" comes as "0",
hence no highlight after line break.

Changed SimpleShaper::advance to take int instead of unsigned.

BUG=521047
Please Note: It was regression caused by https://codereview.chromium.org/608413002

Committed: https://crrev.com/bb8a0772750a23c96d210d8e54cee4b4327611ad
Cr-Commit-Position: refs/heads/master@{#353100}

[Sk.kumar, 2015-10-08 13:13:46]

sk.kumar@samsung.com changed reviewers:
+ eae@chromium.org, pdr@chromium.org, wkorman@chromium.org

[Sk.kumar, 2015-10-08 13:17:00]

pdr@, Please review.

Please note: this is same as https://codereview.chromium.org/1305953003/
But due to blink merge, it couldn't get committed.

[wkorman, 2015-10-08 17:00:55]

lgtm

LGTM but I have no OWNERS so you'll still need pdr/eae.

[pdr., 2015-10-08 17:26:14]

The CQ bit was checked by pdr@chromium.org

[pdr., 2015-10-08 17:26:14]

lgtm

[commit-bot: I haz the power, 2015-10-08 17:26:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1394833002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1394833002/1

[commit-bot: I haz the power, 2015-10-08 18:38:35]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-08 18:40:27]

Patchset 1 (id:??) landed as
https://crrev.com/bb8a0772750a23c96d210d8e54cee4b4327611ad
Cr-Commit-Position: refs/heads/master@{#353100}