Remove usages of WebContents::GetRenderViewHost().

This CL was uploaded by git cl split.

R=avi@chromium.org

Bug: 1142671
Change-Id: Ic9abe2e32995cdd2f1e50ae5b86d8980fc167e9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2501121
Auto-Submit: Lucas Gadani <lfg@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821089}

chrome/browser/ui/hung_renderer/hung_renderer_interactive_uitest.cc

@@ -46,7 +46,7 @@ IN_PROC_BROWSER_TEST_F(HungRendererNavigationTest,
       browser()->tab_strip_model()->GetActiveWebContents();
   TabDialogs::FromWebContents(active_web_contents)
       ->ShowHungRendererDialog(
-          active_web_contents->GetRenderViewHost()->GetWidget(),
+          active_web_contents->GetMainFrame()->GetRenderViewHost()->GetWidget(),
           base::DoNothing::Repeatedly());
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL("b.com", "/title2.html"));