Add keyboard handler for mime-handler-view.

Add keyboard handler for mime-handler-view.

BUG=411753
Test=With mime handler view turned on, click on a PDF to
focus the plugin, now send some keyboard event, like CTRL+L.
See the keyboard event work, i.e. the chrome address bar gets focus.

Committed: https://crrev.com/3895fc1cf74afc344677112d00ad31b0d3311807
Cr-Commit-Position: refs/heads/master@{#293868}

[lazyboy, 2014-09-08 21:48:36]

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

[lazyboy, 2014-09-08 21:48:36]

https://chromiumcodereview.appspot.com/557523002/diff/1/extensions/browser/gu...
File extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
(right):

https://chromiumcodereview.appspot.com/557523002/diff/1/extensions/browser/gu...
extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc:107:
// additional key events. This needs to be fixed as soon as possible.
I'm not sure if the comment is relevant for mime-handler-view.

[Fady Samuel, 2014-09-08 21:51:38]

LGTM

https://codereview.chromium.org/557523002/diff/1/extensions/browser/guest_vie...
File extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
(right):

https://codereview.chromium.org/557523002/diff/1/extensions/browser/guest_vie...
extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc:107:
// additional key events. This needs to be fixed as soon as possible.
On 2014/09/08 21:48:36, lazyboy wrote:
> I'm not sure if the comment is relevant for mime-handler-view.

Yes, it is still relevant unfortunately.

[lazyboy, 2014-09-08 21:52:39]

The CQ bit was checked by lazyboy@chromium.org

[commit-bot: I haz the power, 2014-09-08 21:56:49]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/lazyboy@chromium.org/557523002/1

[commit-bot: I haz the power, 2014-09-09 05:13:28]

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

[commit-bot: I haz the power, 2014-09-09 05:13:29]

Exceeded time limit waiting for builds to trigger.

[Fady Samuel, 2014-09-09 05:23:13]

The CQ bit was checked by fsamuel@chromium.org

[commit-bot: I haz the power, 2014-09-09 05:31:12]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/lazyboy@chromium.org/557523002/1

[commit-bot: I haz the power, 2014-09-09 06:20:53]

Committed patchset #1 (id:1) as 37f1bd32522c1afa72eaf6a37143d82bffa3a0fe

[commit-bot: I haz the power, 2014-09-10 03:51:00]

Patchset 1 (id:??) landed as
https://crrev.com/3895fc1cf74afc344677112d00ad31b0d3311807
Cr-Commit-Position: refs/heads/master@{#293868}