Pepper: Add PepperFileSystemBrowserHost::GotFileSystemContext method.
This will make it easier to do common setup work that requires having the
FileSystemContext, such as setting up Quota checking.

The new GotFileSystemContext method takes a callback to finish opening
each different kind of file system.

This change also renames some callbacks to be a little more consistent.

BUG=194304

Review URL: https://codereview.chromium.org/93403002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238303 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238303
Clean up ChromeContentBrowserClient::ShouldSwapProcessesForNavigation.

The current logic forces a BrowsingInstance swap when going to/from
hosted apps, which breaks postMessage.  Rely on RenderViewHostManager
to do a SiteInstance swap instead.

BUG=123007
TEST=postMessage works after navigating a hosted app popup cross-process.

Review URL: https://codereview.chromium.org/86973002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238304 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238304