Remove usages of WebContents::GetRenderViewHost().

This CL was uploaded by git cl split.

R=sadrul@chromium.org

Bug: 1142671
Change-Id: Idf1a6a3c792f968c39a3f22eea057d58b35f6c24
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2501126
Auto-Submit: Lucas Gadani <lfg@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821067}

content/browser/renderer_host/input/event_latency_aura_browsertest.cc

@@ -28,8 +28,11 @@ class EventLatencyBrowserTest : public ContentBrowserTest {
 
  protected:
   RenderWidgetHostImpl* GetWidgetHost() {
-    return RenderWidgetHostImpl::From(
-        shell()->web_contents()->GetRenderViewHost()->GetWidget());
+    return RenderWidgetHostImpl::From(shell()
+                                          ->web_contents()
+                                          ->GetMainFrame()
+                                          ->GetRenderViewHost()
+                                          ->GetWidget());
   }
 
   // Starts the test server and navigates to the test page. Returns after the