blob: 797c05bb5cc35df851d1dd83894ae8b7c96e8d7e [file] [log] [blame]
// Copyright (c) 2012 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/prerender/prerender_helper.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/histogram.h"
#include "chrome/common/prerender_messages.h"
#include "content/public/renderer/document_state.h"
#include "content/public/renderer/render_frame.h"
#include "content/public/renderer/render_view.h"
#include "third_party/WebKit/public/web/WebFrame.h"
#include "third_party/WebKit/public/web/WebView.h"
using content::DocumentState;
namespace {
// Updates the visibility state of the RenderFrame. Must be called whenever
// prerendering starts or finishes and the page is about to be show. At both
// those times, the RenderFrame is hidden.
void UpdateVisibilityState(content::RenderFrame* render_frame) {
// TODO(jam): until the prerendering code works on frames instead of views, we
// have to do this awkward check.
content::RenderView* render_view = render_frame->GetRenderView();
if (render_view->GetMainRenderFrame() == render_frame) {
render_view->GetVisibilityState(), false);
} // namespace
namespace prerender {
PrerenderHelper::PrerenderHelper(content::RenderFrame* render_frame)
: content::RenderFrameObserver(render_frame),
content::RenderFrameObserverTracker<PrerenderHelper>(render_frame) {
PrerenderHelper::~PrerenderHelper() {
// static.
bool PrerenderHelper::IsPrerendering(const content::RenderFrame* render_frame) {
return PrerenderHelper::Get(render_frame) != NULL;
bool PrerenderHelper::OnMessageReceived(
const IPC::Message& message) {
IPC_BEGIN_MESSAGE_MAP(PrerenderHelper, message)
IPC_MESSAGE_HANDLER(PrerenderMsg_SetIsPrerendering, OnSetIsPrerendering)
// Return false on ViewMsg_SetIsPrerendering so other observers can see the
// message.
return false;
void PrerenderHelper::OnSetIsPrerendering(bool is_prerendering) {
// Immediately after construction, |this| may receive the message that
// triggered its creation. If so, ignore it.
if (is_prerendering)
content::RenderFrame* frame = render_frame();
// |this| must be deleted so PrerenderHelper::IsPrerendering returns false
// when the visibility state is updated, so the visibility state string will
// not be "prerendered".
delete this;
} // namespace prerender