Remove usages of WebContents::GetRenderViewHost().

This CL was uploaded by git cl split.

R=bbudge@chromium.org

Bug: 1142671
Change-Id: I49c4cbda8bad1f164956289c7ee1bb9533330d4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2500492
Auto-Submit: Lucas Gadani <lfg@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821233}

chrome/test/ppapi/ppapi_test.cc

@@ -320,8 +320,11 @@ void OutOfProcessPPAPITest::RunTouchEventTest(const std::string& test_case) {
   RunTest(test_case);
   blink::SyntheticWebTouchEvent touchEvent;
   touchEvent.PressPoint(5, 5);
-  RenderViewHost* rvh =
-      browser()->tab_strip_model()->GetActiveWebContents()->GetRenderViewHost();
+  RenderViewHost* rvh = browser()
+                            ->tab_strip_model()
+                            ->GetActiveWebContents()
+                            ->GetMainFrame()
+                            ->GetRenderViewHost();
   auto watcher = content::RenderViewHostTester::CreateInputWatcher(
       rvh, blink::WebInputEvent::Type::kTouchStart);