Instead of guessing, compute center point of Guest View for test.

Instead of guessing, compute center point of Guest View for test.

The CL modifies WebViewFocusTest.TouchFocusesEmbedder to compute the
center of the Guest View as the target for the synthetic touch event,
instead of just guessing at the coordinate.

BUG=503499
Committed: https://crrev.com/f293d2be06ee72ea958b35c83336d0ebbe1bcbf6
Cr-Commit-Position: refs/heads/master@{#335837}

[wjmaclean, 2015-06-23 22:12:38]

The CQ bit was checked by wjmaclean@chromium.org to run a CQ dry run

[wjmaclean, 2015-06-23 22:12:53]

wjmaclean@chromium.org changed reviewers:
+ lazyboy@chromium.org

[wjmaclean, 2015-06-23 22:13:55]

lazyboy@ - I'm doing to dry-run to make sure this doesn't upset the CQ bots, but
let me know if it looks ok in principle.

[commit-bot: I haz the power, 2015-06-23 22:14:36]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1199313002/1

[lazyboy, 2015-06-23 22:27:50]

lgtm

[commit-bot: I haz the power, 2015-06-23 23:22:26]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-23 23:22:27]

Dry run: This issue passed the CQ dry run.

[wjmaclean, 2015-06-24 00:57:24]

The CQ bit was checked by wjmaclean@chromium.org

[commit-bot: I haz the power, 2015-06-24 00:57:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1199313002/1

[commit-bot: I haz the power, 2015-06-24 01:05:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-24 01:06:34]

Patchset 1 (id:??) landed as
https://crrev.com/f293d2be06ee72ea958b35c83336d0ebbe1bcbf6
Cr-Commit-Position: refs/heads/master@{#335837}