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
2 files changed