Rename the chrome/browser/ui/app_modal directory to be javascript_dialogs.

It will be the future home of the JavaScript dialog tab helper code, which will not be app-modal, so the name is no longer appropriate for use.

In addition, I'm the owner of the existing dialog code (components/app_modal) so I'm going to claim ownership of the new code.

BUG=629964
TEST=none

Review-Url: https://codereview.chromium.org/2169593003
Cr-Commit-Position: refs/heads/master@{#406920}
8 files changed