japhet@ do you know how we would go about doing this? You don't need to actually make the change, but if you or dcheng@ knows where to start and could explain it here we could find someone. :)

For experimentation, we could just try not calling ProgressTracker::progressStarted() or have it return early without doing anything. The main advantage is this should require very few changes. But there are disadvantages as well:
- The frame load might not get recorded in the inspector instrumentation.
- This won't fire the FrameHostMsg_DidStartLoading IPC, which means a lot of things like https://code.google.com/p/chromium/codesearch#chromium/src/content/public/browser/web_contents_observer.h&l=185&gs=cpp:content::class-WebContentsObserver::DidStartLoading()@chromium/../../content/public/browser/web_contents_observer.h%257Cdef&gsn=DidStartLoading&ct=xref_usages won't run.

Another alternative is to try tweaking the bits in https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/frame_host/frame_tree_node.cc&rcl=1461107913&l=382 and https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/frame_host/frame_tree.cc&rcl=1461107913&l=407 so it only affects the UI, but it gets more complicated.

Is this similar to issue 573177?

I'm a bit concerned about hiding loading indicators. It is reality that the page might be navigating/loading an iframe, which can be off-screen. I doubt hiding this fact from the user is a good UX as clearly we are transferring data/loading document.

https://codereview.chromium.org/1860743002/ is my WIP for making the loading progress bar main-frame-only (and stopping after DOMContentLoaded instead of load). I believe this *only* changes the progress bar, so the stop button will still be shown until everything in all the iframes are done.

Renaming Blink>Architecture to Blink>Internals

This is shipped.