Add a ProxyPolicyProvider to BrowserPolicyConnectorIos.

This will allow user cloud policy to override preferences in Local State,
which is required to implement some policies such as MetricsReportingEnabled.

BUG=275292
R=dconnelly@chromium.org

Review URL: https://codereview.chromium.org/145263003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246831 0039d316-1c4b-4281-b951-d872f2087c98
Have a central operation status code for ServiceWorker

Could we have something like it?

We'll still need some if/switch code in each module to filter out
irrelevant status code, but having a central status code usually
makes things easier:
- less switch/case between small module boundaries
- single StatusCodeToString method for error reporting and debugging

BUG=285976
R=alecflett@chromium.org
TBR=jam

Review URL: https://codereview.chromium.org/142973003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246832 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246832