Move LoadProgressTracker to the browser process.

content/browser/frame_host/render_frame_host_delegate.h

Index: content/browser/frame_host/render_frame_host_delegate.h
diff --git a/content/browser/frame_host/render_frame_host_delegate.h b/content/browser/frame_host/render_frame_host_delegate.h
index b1a15236a59fea955f2ce8addd79f5272de6919a..99bb29e00d8db543bb9ced96a64cba3745164d20 100644
--- a/content/browser/frame_host/render_frame_host_delegate.h
+++ b/content/browser/frame_host/render_frame_host_delegate.h
@@ -44,17 +44,12 @@ class CONTENT_EXPORT RenderFrameHostDelegate {
   // Informs the delegate whenever a RenderFrameHost is deleted.
   virtual void RenderFrameDeleted(RenderFrameHost* render_frame_host) {}
 
-  // The top-level RenderFrame began loading a new page. This corresponds to
-  // Blink's notion of the throbber starting.
-  // |to_different_document| will be true unless the load is a fragment
-  // navigation, or triggered by history.pushState/replaceState.
+  // The top-level RenderFrame began loading a new page. The presence of this
+  // function in RenderFrameHostDelegate is a hack to allow the RenderFrameHost
+  // to force a loading spinner to show up; TODO(avi): Remove this.

[nasko, 2014/05/05 23:51:12]

I'm not sure that this is a hack. It seems this is used to intentionally
indicate that a load has started as soon as possible in the case of
browser-initiated navigation. 

[Avi (use Gerrit), 2014/05/06 00:03:40]

It feels unbalanced to me. At points we have to force the UI to stop too, and it
doesn't flow well.

I'll revert this comment, but the current structure feels off.

   virtual void DidStartLoading(RenderFrameHost* render_frame_host,
                                bool to_different_document) {}
 
-  // The top-level RenderFrame stopped loading a page. This corresponds to
-  // Blink's notion of the throbber stopping.
-  virtual void DidStopLoading(RenderFrameHost* render_frame_host) {}
-
   // The RenderFrameHost has been swapped out.
   virtual void SwappedOut(RenderFrameHost* render_frame_host) {}