Disable Screen Orientation API locking ability for WebView.

Disable Screen Orientation API locking ability for WebView.

This CL is adding a content switch that is used by WebView to not create
a ScreenOrientationDelegate which will prevent locking to work on WebView
and will correctly return that locking isn't supported to Javascript.

BUG=466080
Committed: https://crrev.com/8ded9764c2691fc4682c6640beb410bebdc6b35e
Cr-Commit-Position: refs/heads/master@{#322404}

[Torne, 2015-03-25 16:16:40]

torne@chromium.org changed reviewers:
+ torne@chromium.org

[Torne, 2015-03-25 16:16:41]

lgtm. tested this on a webview build and the API now correctly reports not
supported.

[mlamouri (slow - plz ping), 2015-03-25 16:39:03]

mlamouri@chromium.org changed reviewers:
+ jochen@chromium.org

[mlamouri (slow - plz ping), 2015-03-25 16:39:04]

Jochen, this is a M42 stable blocker for WebView.

[jochen (gone - plz use gerrit), 2015-03-26 15:33:05]

lgtm

[mlamouri (slow - plz ping), 2015-03-26 15:51:52]

The CQ bit was checked by mlamouri@chromium.org

[commit-bot: I haz the power, 2015-03-26 15:52:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1037693003/60001

[commit-bot: I haz the power, 2015-03-26 17:06:36]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-03-26 17:07:18]

Patchset 4 (id:??) landed as
https://crrev.com/8ded9764c2691fc4682c6640beb410bebdc6b35e
Cr-Commit-Position: refs/heads/master@{#322404}