Was asked to file this by dgozman@chromium.org

The debugger protocol previously had Page.setControlNavigations and Page.processNavigation APIs, which were useful for preventing redirects and unwanted navigation. The preferred API for accomplishing this is now Network.setRequestInterceptionEnabled.

The problem with relying on this API is that there is no way to tell the page that the redirect/navigation request came from, or the target of that request.

For example: if an iframe redirects itself, that is OK, and the request should be allowed. If an iframe tries to redirect the top-level page, however, this may need to be blocked.

Link to conversation thread: https://groups.google.com/forum/#!topic/chrome-debugging-protocol/-v4jAkavho0