Cleanup: Move kFileSystemScheme constant into content namespace.

BUG=None
TEST=None
TBR=jam@chromium.org

Review URL: https://codereview.chromium.org/104043010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242336 0039d316-1c4b-4281-b951-d872f2087c98
Certificate Transparency: Threading the SCT IDs & Status list.
This is going to be used by the Signed Certificate Timestamps viewer,
which will be accessible from the website settings popup.

This change, by itself, does not add any new functionality but will
decrease the size of the next patch, the actual implementation for the
SCT viewer.

BUG=309578

Review URL: https://codereview.chromium.org/109373003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242337 0039d316-1c4b-4281-b951-d872f2087c98
Update the pageaction_by_url sample to use declarativeContent
and avoid the tabs permission.

BUG=330359

Review URL: https://codereview.chromium.org/109983004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242338 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242338