New link rel=prerender api, using WebKit::WebPrerenderingPlatform

chrome/browser/prerender/prerender_message_filter.cc

+// 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/browser/prerender/prerender_message_filter.h"
+
+#include "base/bind.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/prerender/prerender_link_manager.h"
+#include "chrome/browser/prerender/prerender_link_manager_factory.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/common/prerender_messages.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace {
+
+void OnChannelClosingInUIThread(Profile* profile, int render_process_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (!g_browser_process->profile_manager()->IsValidProfile(profile))
+    return;
+  prerender::PrerenderLinkManager* prerender_link_manager =
+      prerender::PrerenderLinkManagerFactory::GetForProfile(profile);
+  if (!prerender_link_manager)
+    return;
+  prerender_link_manager->OnChannelClosing(render_process_id);
+}
+
+}  // anon namespace

[dominich, 2012/04/26 22:50:58]

nit: // end namespace

[gavinp, 2012/04/27 20:31:32]

Done, also in prerenderer_client.cc, and added the omitted one in
prerender_link_manager.cc.

+
+namespace prerender {
+
+PrerenderMessageFilter::PrerenderMessageFilter(int render_process_id,
+                                               Profile* profile)
+    : render_process_id_(render_process_id),
+      profile_(profile) {
+}
+
+bool PrerenderMessageFilter::OnMessageReceived(const IPC::Message& message,
+                                               bool* message_was_ok) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP_EX(PrerenderMessageFilter, message, *message_was_ok)
+    IPC_MESSAGE_HANDLER(PrerenderHostMsg_AddPrerender, OnAddPrerender)
+    IPC_MESSAGE_HANDLER(PrerenderHostMsg_CancelPrerender, OnCancelPrerender)
+    IPC_MESSAGE_HANDLER(PrerenderHostMsg_AbandonPrerender, OnAbandonPrerender)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+
+  return handled;
+}
+
+void PrerenderMessageFilter::OverrideThreadForMessage(
+    const IPC::Message& message, content::BrowserThread::ID* thread) {
+  if (message.type() == PrerenderHostMsg_AddPrerender::ID ||

[jam, 2012/04/27 15:59:50]

nit, you can just write

if (IPC_MESSAGE_CLASS(message) == PrerenderMsgStart))
  *thread =...

[gavinp, 2012/04/27 20:31:32]

I'm scared to do that: what if someone later adds another prerender message, say
a routed one, to a browser?  Would this force that surprisingly onto the UI
thread?  In prerendering, we have launcher contexts (i.e. any webpage), and
prerender contexts (i.e. pages being prerendered), so it's really reasonable to
expect this to happen in the future, and not use this message_filter, but
instead one that's only installed on prerendered pages?

Given that, does it make sense to leave this as it is?

+      message.type() == PrerenderHostMsg_CancelPrerender::ID ||
+      message.type() == PrerenderHostMsg_AbandonPrerender::ID) {
+    *thread = BrowserThread::UI;
+  }
+}
+
+PrerenderMessageFilter::~PrerenderMessageFilter() {
+}
+
+void PrerenderMessageFilter::OnAddPrerender(
+    int prerender_id,
+    const GURL& url,
+    const content::Referrer& referrer,
+    const gfx::Size& size,
+    int render_view_route_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  PrerenderLinkManager* prerender_link_manager =
+      PrerenderLinkManagerFactory::GetForProfile(profile_);
+  if (!prerender_link_manager)
+    return;
+  prerender_link_manager->OnAddPrerender(
+      render_process_id_, prerender_id,
+      url, referrer, size, render_view_route_id);
+}
+
+void PrerenderMessageFilter::OnCancelPrerender(
+    int prerender_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  PrerenderLinkManager* prerender_link_manager =
+      PrerenderLinkManagerFactory::GetForProfile(profile_);
+  if (!prerender_link_manager)
+    return;
+  prerender_link_manager->OnCancelPrerender(
+      prerender_id, render_process_id_);
+}
+
+void PrerenderMessageFilter::OnAbandonPrerender(
+    int prerender_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  PrerenderLinkManager* prerender_link_manager =
+      PrerenderLinkManagerFactory::GetForProfile(profile_);
+  if (!prerender_link_manager)
+    return;
+  prerender_link_manager->OnAbandonPrerender(
+      prerender_id, render_process_id_);
+}
+
+void PrerenderMessageFilter::OnChannelClosing() {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&OnChannelClosingInUIThread, profile_, render_process_id_));
+}
+
+}  // namespace prerender
+