Make the renderer-side prerendering code use RenderFrames instead of RenderViews.

chrome/renderer/chrome_render_frame_observer.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/renderer/chrome_render_frame_observer.h"
+
+#include "chrome/common/prerender_messages.h"
+#include "chrome/renderer/prerender/prerender_helper.h"
+
+ChromeRenderFrameObserver::ChromeRenderFrameObserver(
+    content::RenderFrame* render_frame)
+    : content::RenderFrameObserver(render_frame) {
+}
+
+ChromeRenderFrameObserver::~ChromeRenderFrameObserver() {
+}
+
+bool ChromeRenderFrameObserver::OnMessageReceived(const IPC::Message& message) {
+  // Filter only.
+  IPC_BEGIN_MESSAGE_MAP(ChromeRenderFrameObserver, message)
+    IPC_MESSAGE_HANDLER(PrerenderMsg_SetIsPrerendering, OnSetIsPrerendering);
+  IPC_END_MESSAGE_MAP()
+
+  return false;
+}
+
+void ChromeRenderFrameObserver::OnSetIsPrerendering(bool is_prerendering) {
+  if (is_prerendering) {
+    DCHECK(!prerender::PrerenderHelper::Get(render_frame()));
+    // The PrerenderHelper will destroy itself either after recording histograms
+    // or on destruction of the RenderView.
+    new prerender::PrerenderHelper(render_frame());
+  }
+}