Update gypi in extensions after move and removal of headers.

Update gypi in extensions after move and removal of headers.

Fixes warnings in the gyp msvs-ninja generator.

Followup to
https://codereview.chromium.org/892923002 (guest_view_messages.h)
https://codereview.chromium.org/913393003 (extension_view.js)
https://codereview.chromium.org/820513002 (surface_worker.js,
    and surface_view.js)
https://codereview.chromium.org/654043002 (web_view.js,
    web_view_events.js and web_view_experimental.js)

R=fsamuel@chromium.org,kalman@chromium.org,apacible@chromium.org,rockot@chromium.org
BUG=459058, 444869, 459680, 434226
Committed: https://crrev.com/400e3ecf9e6456f00c8626b33188933c63696941
Cr-Commit-Position: refs/heads/master@{#317767}

[Fady Samuel, 2015-02-23 15:35:25]

lgtm

[apacible, 2015-02-23 16:32:58]

lgtm

[Ken Rockot(use gerrit already), 2015-02-23 17:25:30]

lgtm

[Daniel Bratell, 2015-02-23 17:34:50]

The CQ bit was checked by bratell@opera.com

[commit-bot: I haz the power, 2015-02-23 17:35:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/952513002/1

[commit-bot: I haz the power, 2015-02-23 17:41:01]

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

[commit-bot: I haz the power, 2015-02-23 17:41:02]

Try jobs failed on following builders:
  ios_dbg_simulator on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_dbg_simulator...)

[Daniel Bratell, 2015-02-24 08:32:12]

The CQ bit was checked by bratell@opera.com

[commit-bot: I haz the power, 2015-02-24 08:32:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/952513002/1

[commit-bot: I haz the power, 2015-02-24 08:46:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-24 08:46:56]

Patchset 1 (id:??) landed as
https://crrev.com/400e3ecf9e6456f00c8626b33188933c63696941
Cr-Commit-Position: refs/heads/master@{#317767}