Deleted experimental.discovery API from the code base

The only use of the API was in chrome/browser/ui/webui/ntp which
combined the suggestions from the discovery API with others.

Also removed the documentation from the docserver, and bumped the yaml
versions.

BUG=304834

Review URL: https://codereview.chromium.org/116603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245056 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245056
Resubmit of imageWriterPrivate.destroyPartitions

Previous CL: https://codereview.chromium.org/109793006/

BUG=328246

Review URL: https://codereview.chromium.org/119963009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245059 0039d316-1c4b-4281-b951-d872f2087c98
Handle automatic updates of cached ephemeral apps

Fixed a few issues that occur when cached ephemeral apps are
automatically updated by the extension system:
- The new version of the app should also have the ephemeral flag
enabled. Previously, the flag was switched off, causing the app to
be installed on update.
- Prompt on next launch if the new version requests more permissions.
- Ensure that notifications do not appear in the UI if a cached
ephemeral app is updated and requests more permissions.

BUG=312460
TEST=browser_tests (EphemeralAppBrowserTest.*)

Review URL: https://codereview.chromium.org/127603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245060 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245060
Support calling setMetaData after start for WebRTC logging.

Patch set 5 credits to vrk@.

BUG=332190

Review URL: https://codereview.chromium.org/128403002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245062 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245062