Add webview sample for captureVisibleRegion().

Add webview sample for captureVisibleRegion().

App allows the webview to be created both with and without
allowtransparency.

BUG=600496
Committed: https://crrev.com/bc79c30f2651c40d4bd5b219b22bfc6985e27679
Cr-Commit-Position: refs/heads/master@{#385834}

[avallee, 2016-04-06 18:53:24]

avallee@chromium.org changed reviewers:
+ paulmeyer@chromium.org

[avallee, 2016-04-06 18:53:25]

PTAL.

[paulmeyer, 2016-04-07 18:41:50]

lgtm

[avallee, 2016-04-07 18:42:25]

The CQ bit was checked by avallee@chromium.org

[commit-bot: I haz the power, 2016-04-07 18:43:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1869533002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1869533002/1

[commit-bot: I haz the power, 2016-04-07 19:20:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-07 19:23:40]

Description was changed from

==========
Add webview sample for captureVisibleRegion().

App allows the webview to be created both with and without
allowtransparency.

BUG=600496
==========

to

==========
Add webview sample for captureVisibleRegion().

App allows the webview to be created both with and without
allowtransparency.

BUG=600496

Committed: https://crrev.com/bc79c30f2651c40d4bd5b219b22bfc6985e27679
Cr-Commit-Position: refs/heads/master@{#385834}
==========

[commit-bot: I haz the power, 2016-04-07 19:23:41]

Patchset 1 (id:??) landed as
https://crrev.com/bc79c30f2651c40d4bd5b219b22bfc6985e27679
Cr-Commit-Position: refs/heads/master@{#385834}