Allow webstore extensions to use experimental permissions.

Allow webstore extensions to use experimental permissions. We
will rely on the store to enforce that normal extensions do 
not contain 'experimental'.

Also simplify some code in ExtensionService, Extension, and extension_manifest_unittest.cc.

BUG=100487
TBR=jstritar@chromium.org


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=105734

[commit-bot: I haz the power, 2011-10-16 14:22:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/aa@chromium.org/8313006/1006

[commit-bot: I haz the power, 2011-10-16 14:22:22]

Can't apply patch for file chrome/common/extensions/extension.cc.
While running patch -p1 --forward --force;
patching file chrome/common/extensions/extension.cc
Hunk #5 FAILED at 1982.
Hunk #6 succeeded at 2092 (offset -2 lines).
Hunk #7 succeeded at 2619 (offset -2 lines).
Hunk #8 succeeded at 2756 (offset -2 lines).
Hunk #9 succeeded at 2827 with fuzz 1 (offset 5 lines).
1 out of 9 hunks FAILED -- saving rejects to file
chrome/common/extensions/extension.cc.rej

[commit-bot: I haz the power, 2011-10-16 14:53:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/aa@chromium.org/8313006/3001

[commit-bot: I haz the power, 2011-10-16 16:23:20]

Change committed as 105734

[Mihai Parparita -not on Chrome, 2011-10-16 22:41:45]

http://codereview.chromium.org/8313006/diff/3001/chrome/browser/extensions/ex...
File chrome/browser/extensions/extension_service.cc (right):

http://codereview.chromium.org/8313006/diff/3001/chrome/browser/extensions/ex...
chrome/browser/extensions/extension_service.cc:1453: int
ExtensionService::GetExtensionCreateFlagsForInstalledExtension(
Seems like this could be a static/in an unnamed namespace function in this file.

http://codereview.chromium.org/8313006/diff/3001/chrome/browser/extensions/ex...
chrome/browser/extensions/extension_service.cc:1456: if
(info->extension_location != Extension::LOAD)
Body is indented one too many times.