WebTest: Remove RenderViewHost for main window

A flag to check if a new RenderFrameHost is really new in
WebTestControlHost::HandleNewRenderFrameHost(),
we check if its RenderViewHost is already contained in
|main_window_render_view_hosts_|.

This detection is based on our past design that we don't
delete RenderViewHosts in a web test, and we don't erase
entries of |main_window_render_view_hosts_|.
But it can happen if we start to swap RenderFrameHosts and
RenderViewHosts with Browsing Instance Swap and/or
Back-Forward Cache.

After deleting an old RenderViewHost, a new RenderViewHost
can be created on the address where the old one was allocated.
This address conflict can lead a misjudge of the check of
new RenderFrameHosts.

This CL handles delete events of RenderViewHosts for main
windows on WebTestControlHost, and removes their addresses
from the list.


Bug: 1136383, 1132180
Change-Id: I442ad67d2207a822dec37fb676d623dd035f0b9d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2462997
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Reviewed-by: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816630}

content/web_test/browser/web_test_control_host.cc

@@ -1065,6 +1065,10 @@ void WebTestControlHost::DidUpdateFaviconURL(
   }
 }
 
+void WebTestControlHost::RenderViewDeleted(RenderViewHost* render_view_host) {
+  main_window_render_view_hosts_.erase(render_view_host);
+}
+
 void WebTestControlHost::RenderProcessHostDestroyed(
     RenderProcessHost* render_process_host) {
   render_process_host_observer_.Remove(render_process_host);

content/web_test/browser/web_test_control_host.h

@@ -159,6 +159,7 @@ class WebTestControlHost : public WebContentsObserver,
   void DidUpdateFaviconURL(
       RenderFrameHost* render_frame_host,
       const std::vector<blink::mojom::FaviconURLPtr>& candidates) override;
+  void RenderViewDeleted(RenderViewHost* render_view_host) override;
 
   // RenderProcessHostObserver implementation.
   void RenderProcessHostDestroyed(