Remove the is_loading_ field from WebContentsImpl

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 76ffb6978383e300095af8f3fea399f3fc6bf03b..da2ad4224db87db6ef3ba6e03944576a802bf5cd 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -4576,10 +4576,9 @@ void RenderFrameImpl::OnFailedNavigation(
       frame_->isViewSourceModeEnabled());
   SendFailedProvisionalLoad(failed_request, error, frame_);
 
+  // This check should have been done on the browser side already.
   if (!ShouldDisplayErrorPageForFailedLoad(error_code, common_params.url)) {
-    // TODO(avi): Remove this; we shouldn't ever be dropping navigations.
-    // http://crbug.com/501960
-    Send(new FrameHostMsg_DidDropNavigation(routing_id_));
+    NOTREACHED();

[nasko, 2016/01/15 01:19:16]

Shouldn't this be CHECK for a short period of time to ensure we don't hit this
in the wild? I think avi@ needs to weigh in on this one.

[Avi (use Gerrit), 2016/01/15 04:48:00]

In the comment when I said that we "shouldn't ever be dropping navigations", I
meant that in a philosophical sense of "it's bad design to drop navigations,
since we only cause weird corner cases, so we should re-design and re-work
Chrome to not do that." Perhaps my comment wasn't as clear as it could be.

In any case, I did not mean NOTREACHED. ShouldDisplayErrorPageForFailedLoad is
going to return |false| (in fact, the whole point of that function is to
sometimes return true and sometimes false) so to explode it in that case is bad
form.

[clamy, 2016/01/15 16:47:44]

This is is a PlzNavigate only method, and I realize now that it is not properly
indicated. In that case the filtering should be done on the browser side so it
really should be NOTREACHED. I added the proper markings of a PlzNavigate method
to make it clearer.

     return;
   }
 
@@ -5127,6 +5126,11 @@ void RenderFrameImpl::NavigateInternal(
       frame_->toWebLocalFrame()->load(request, load_type,
                                       item_for_history_navigation);
     }
+  } else {
+    // The browser expects the frame to be loading this navigation. Informs it

[nasko, 2016/01/15 01:19:16]

Inform

[clamy, 2016/01/15 16:47:44]

Done.

+    // that the load stopped if needed.
+    if (!frame_->isLoading())
+      Send(new FrameHostMsg_DidStopLoading(routing_id_));
   }
 
   // In case LoadRequest failed before didCreateDataSource was called.