Remove usages of WebContents::GetRenderViewHost().

This CL was uploaded by git cl split.

R=tiborg@chromium.org

Bug: 1142671
Change-Id: Ie2aff35d42822e95da7a00b10c1d0e791998e25c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2500490
Auto-Submit: Lucas Gadani <lfg@chromium.org>
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Commit-Queue: Tibor Goldschwendt <tiborg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821338}

chrome/browser/ui/search/local_ntp_render_browsertest.cc

@@ -70,7 +70,7 @@ class LocalNTPRenderTest : public InProcessBrowserTest {
     content::RenderFrameSubmissionObserver render_frame_observer(active_tab);
 
     content::RenderWidgetHost* render_widget_host =
-        active_tab->GetRenderViewHost()->GetWidget();
+        active_tab->GetMainFrame()->GetRenderViewHost()->GetWidget();
     content::RenderWidgetHostView* view = render_widget_host->GetView();
     ASSERT_TRUE(view && view->IsSurfaceAvailableForCopy());