Add <link rel=next> support to prerender.

IEs prerender implementation supports rel=next link elements. Let's
also parse them, and based on a field trial launch these as
prerenders.

R=davidben,tburkard,jochen,jschuh@chromium.org
BUG=329963

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=250280

Review URL: https://codereview.chromium.org/113803003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250558 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 117 insertions, 22 deletions

diff --git a/chrome/browser/prerender/prerender_link_manager.cc b/chrome/browser/prerender/prerender_link_manager.cc
index 8213ded..30846b4 100644
--- a/chrome/browser/prerender/prerender_link_manager.cc
+++ b/chrome/browser/prerender/prerender_link_manager.cc
@@ -7,15 +7,18 @@
 #include <functional>
 #include <limits>
 #include <set>
+#include <string>
 #include <utility>
 
 #include "base/memory/scoped_ptr.h"
+#include "base/metrics/field_trial.h"
 #include "chrome/browser/prerender/prerender_contents.h"
 #include "chrome/browser/prerender/prerender_handle.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/prerender_messages.h"
+#include "chrome/common/prerender_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/session_storage_namespace.h"
@@ -28,8 +31,30 @@ using base::TimeTicks;
 using content::RenderViewHost;
 using content::SessionStorageNamespace;
 
+namespace prerender {
+
 namespace {
 
+bool ShouldStartRelNextPrerenders() {
+  const std::string experiment_name =
+      base::FieldTrialList::FindFullName("PrerenderRelNextTrial");
+
+  return experiment_name.find("Yes") != std::string::npos;
+}
+
+bool ShouldStartPrerender(uint32 rel_types) {
+  const bool should_start_rel_next_prerenders =
+      ShouldStartRelNextPrerenders();
+
+  if (rel_types & PrerenderRelTypePrerender) {
+    return true;
+  } else if (should_start_rel_next_prerenders &&
+             (rel_types & PrerenderRelTypeNext) == PrerenderRelTypeNext) {
+    return true;
+  }
+  return false;
+}
+
 void Send(int child_id, IPC::Message* raw_message) {
   using content::RenderProcessHost;
   scoped_ptr<IPC::Message> own_message(raw_message);
@@ -42,8 +67,6 @@ void Send(int child_id, IPC::Message* raw_message) {
 
 }  // namespace
 
-namespace prerender {
-
 // Helper class to implement PrerenderContents::Observer and watch prerenders
 // which launch other prerenders.
 class PrerenderLinkManager::PendingPrerenderManager
@@ -109,6 +132,7 @@ PrerenderLinkManager::~PrerenderLinkManager() {
 void PrerenderLinkManager::OnAddPrerender(int launcher_child_id,
                                           int prerender_id,
                                           const GURL& url,
+                                          uint32 rel_types,
                                           const content::Referrer& referrer,
                                           const gfx::Size& size,
                                           int render_view_route_id) {
@@ -135,7 +159,7 @@ void PrerenderLinkManager::OnAddPrerender(int launcher_child_id,
   }
 
   LinkPrerender
-      prerender(launcher_child_id, prerender_id, url, referrer, size,
+      prerender(launcher_child_id, prerender_id, url, rel_types, referrer, size,
                 render_view_route_id, manager_->GetCurrentTimeTicks(),
                 prerender_contents);
   prerenders_.push_back(prerender);
@@ -196,6 +220,7 @@ PrerenderLinkManager::LinkPrerender::LinkPrerender(
     int launcher_child_id,
     int prerender_id,
     const GURL& url,
+    uint32 rel_types,
     const content::Referrer& referrer,
     const gfx::Size& size,
     int render_view_route_id,
@@ -204,6 +229,7 @@ PrerenderLinkManager::LinkPrerender::LinkPrerender(
     : launcher_child_id(launcher_child_id),
       prerender_id(prerender_id),
       url(url),
+      rel_types(rel_types),
       referrer(referrer),
       size(size),
       render_view_route_id(render_view_route_id),
@@ -314,6 +340,11 @@ void PrerenderLinkManager::StartPrerenders() {
       }
     }
 
+    if (!ShouldStartPrerender((*i)->rel_types)) {
+      prerenders_.erase(*i);
+      continue;
+    }
+
     PrerenderHandle* handle = manager_->AddPrerenderFromLinkRelPrerender(
         (*i)->launcher_child_id, (*i)->render_view_route_id,
         (*i)->url, (*i)->referrer, (*i)->size);
diff --git a/chrome/browser/prerender/prerender_link_manager.h b/chrome/browser/prerender/prerender_link_manager.h
index ec8dbf6..743765d 100644
--- a/chrome/browser/prerender/prerender_link_manager.h
+++ b/chrome/browser/prerender/prerender_link_manager.h
@@ -47,6 +47,7 @@ class PrerenderLinkManager : public BrowserContextKeyedService,
   void OnAddPrerender(int child_id,
                       int prerender_id,
                       const GURL& url,
+                      uint32 rel_types,
                       const content::Referrer& referrer,
                       const gfx::Size& size,
                       int render_view_route_id);
@@ -75,6 +76,7 @@ class PrerenderLinkManager : public BrowserContextKeyedService,
     LinkPrerender(int launcher_child_id,
                   int prerender_id,
                   const GURL& url,
+                  uint32 rel_types,
                   const content::Referrer& referrer,
                   const gfx::Size& size,
                   int render_view_route_id,
@@ -86,6 +88,7 @@ class PrerenderLinkManager : public BrowserContextKeyedService,
     int launcher_child_id;
     int prerender_id;
     GURL url;
+    uint32 rel_types;
     content::Referrer referrer;
     gfx::Size size;
     int render_view_route_id;
@@ -170,4 +173,3 @@ class PrerenderLinkManager : public BrowserContextKeyedService,
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_LINK_MANAGER_H_
-
diff --git a/chrome/browser/prerender/prerender_message_filter.cc b/chrome/browser/prerender/prerender_message_filter.cc
index 2379b55..4f203bd 100644
--- a/chrome/browser/prerender/prerender_message_filter.cc
+++ b/chrome/browser/prerender/prerender_message_filter.cc
@@ -72,7 +72,7 @@ void PrerenderMessageFilter::OnChannelClosing() {
 
 void PrerenderMessageFilter::OnAddPrerender(
     int prerender_id,
-    const GURL& url,
+    const PrerenderAttributes& attributes,
     const content::Referrer& referrer,
     const gfx::Size& size,
     int render_view_route_id) {
@@ -83,7 +83,8 @@ void PrerenderMessageFilter::OnAddPrerender(
     return;
   prerender_link_manager->OnAddPrerender(
       render_process_id_, prerender_id,
-      url, referrer, size, render_view_route_id);
+      attributes.url, attributes.rel_types, referrer,
+      size, render_view_route_id);
 }
 
 void PrerenderMessageFilter::OnCancelPrerender(
diff --git a/chrome/browser/prerender/prerender_message_filter.h b/chrome/browser/prerender/prerender_message_filter.h
index 0d5eb06..a5a7ac6 100644
--- a/chrome/browser/prerender/prerender_message_filter.h
+++ b/chrome/browser/prerender/prerender_message_filter.h
@@ -10,6 +10,7 @@
 #include "url/gurl.h"
 
 class Profile;
+struct PrerenderAttributes;
 
 namespace content {
 struct Referrer;
@@ -41,7 +42,7 @@ class PrerenderMessageFilter : public content::BrowserMessageFilter {
   virtual void OnChannelClosing() OVERRIDE;
 
   void OnAddPrerender(int prerender_id,
-                      const GURL& url,
+                      const PrerenderAttributes& attributes,
                       const content::Referrer& referrer,
                       const gfx::Size& size,
                       int render_view_route_id);
diff --git a/chrome/browser/prerender/prerender_unittest.cc b/chrome/browser/prerender/prerender_unittest.cc
index 8ffb439..055be35 100644
--- a/chrome/browser/prerender/prerender_unittest.cc
+++ b/chrome/browser/prerender/prerender_unittest.cc
@@ -18,6 +18,7 @@
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_origin.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/common/prerender_types.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/browser/render_view_host.h"
@@ -84,6 +85,8 @@ int DummyPrerenderContents::g_next_route_id_ = 0;
 
 const gfx::Size kSize(640, 480);
 
+const uint32 kDefaultRelTypes = PrerenderRelTypePrerender;
+
 }  // namespace
 
 class UnitTestPrerenderManager : public PrerenderManager {
@@ -376,10 +379,9 @@ class PrerenderTest : public testing::Test {
   // true iff the prerender has been added to the PrerenderManager by the
   // PrerenderLinkManager and the PrerenderManager returned a handle.
   bool AddSimplePrerender(const GURL& url) {
-    prerender_link_manager()->OnAddPrerender(kDefaultChildId,
-                                             GetNextPrerenderID(),
-                                             url, content::Referrer(),
-                                             kSize, kDefaultRenderViewRouteId);
+    prerender_link_manager()->OnAddPrerender(
+        kDefaultChildId, GetNextPrerenderID(), url, kDefaultRelTypes,
+        content::Referrer(), kSize, kDefaultRenderViewRouteId);
     return LauncherHasRunningPrerender(kDefaultChildId, last_prerender_id());
   }
 
@@ -719,7 +721,7 @@ TEST_F(PrerenderTest, PendingPrerenderTest) {
           ORIGIN_GWS_PRERENDER,
           FINAL_STATUS_USED);
   prerender_link_manager()->OnAddPrerender(
-      child_id, GetNextPrerenderID(), pending_url,
+      child_id, GetNextPrerenderID(), pending_url, kDefaultRelTypes,
       Referrer(url, blink::WebReferrerPolicyDefault),
       kSize, route_id);
   EXPECT_FALSE(LauncherHasRunningPrerender(child_id, last_prerender_id()));
@@ -760,7 +762,7 @@ TEST_F(PrerenderTest, InvalidPendingPrerenderTest) {
           ORIGIN_GWS_PRERENDER,
           FINAL_STATUS_UNSUPPORTED_SCHEME);
   prerender_link_manager()->OnAddPrerender(
-      child_id, GetNextPrerenderID(), pending_url,
+      child_id, GetNextPrerenderID(), pending_url, kDefaultRelTypes,
       Referrer(url, blink::WebReferrerPolicyDefault),
       kSize, route_id);
   EXPECT_FALSE(LauncherHasRunningPrerender(child_id, last_prerender_id()));
@@ -792,7 +794,7 @@ TEST_F(PrerenderTest, CancelPendingPrerenderTest) {
 
   // Schedule a pending prerender launched from the prerender.
   prerender_link_manager()->OnAddPrerender(
-      child_id, GetNextPrerenderID(), pending_url,
+      child_id, GetNextPrerenderID(), pending_url, kDefaultRelTypes,
       Referrer(url, blink::WebReferrerPolicyDefault),
       kSize, route_id);
   EXPECT_FALSE(LauncherHasRunningPrerender(child_id, last_prerender_id()));
@@ -831,11 +833,40 @@ TEST_F(PrerenderTest, SourceRenderViewClosed) {
   prerender_manager()->CreateNextPrerenderContents(
       url,
       FINAL_STATUS_MANAGER_SHUTDOWN);
-  prerender_link_manager()->OnAddPrerender(100, GetNextPrerenderID(), url,
-                                           Referrer(), kSize, 200);
+  prerender_link_manager()->OnAddPrerender(
+      100, GetNextPrerenderID(), url, kDefaultRelTypes, Referrer(), kSize, 200);
   EXPECT_FALSE(LauncherHasRunningPrerender(100, last_prerender_id()));
 }
 
+// Tests that prerendering doesn't launch rel=next prerenders without the field
+// trial.
+TEST_F(PrerenderTest, NoRelNextByDefault) {
+  GURL url("http://www.google.com/");
+  prerender_manager()->CreateNextPrerenderContents(
+      url, FINAL_STATUS_MANAGER_SHUTDOWN);
+  DummyPrerenderContents* null = NULL;
+
+  prerender_link_manager()->OnAddPrerender(
+      kDefaultChildId, GetNextPrerenderID(), url, PrerenderRelTypeNext,
+      Referrer(), kSize, kDefaultRenderViewRouteId);
+  EXPECT_EQ(null, prerender_manager()->FindEntry(url));
+}
+
+// Tests that prerendering does launch rel=next prerenders with the field trial.
+TEST_F(PrerenderTest, RelNextByFieldTrial) {
+  ASSERT_TRUE(base::FieldTrialList::CreateFieldTrial("PrerenderRelNextTrial",
+                                                     "Yes"));
+  GURL url("http://www.google.com/");
+  DummyPrerenderContents* prerender_contents =
+      prerender_manager()->CreateNextPrerenderContents(
+          url, FINAL_STATUS_USED);
+
+  prerender_link_manager()->OnAddPrerender(
+      kDefaultChildId, GetNextPrerenderID(), url, PrerenderRelTypeNext,
+      Referrer(), kSize, kDefaultRenderViewRouteId);
+  EXPECT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
+}
+
 // Tests that prerendering is cancelled when we launch a second prerender of
 // the same target within a short time interval.
 TEST_F(PrerenderTest, RecentlyVisited) {
@@ -1391,10 +1422,9 @@ TEST_F(PrerenderTest, LinkManagerClearOnPendingAbandon) {
   ASSERT_TRUE(prerender_contents->GetRouteId(&route_id));
 
   GURL pending_url("http://www.neverlaunched.com");
-  prerender_link_manager()->OnAddPrerender(child_id,
-                                           GetNextPrerenderID(),
-                                           pending_url, content::Referrer(),
-                                           kSize, route_id);
+  prerender_link_manager()->OnAddPrerender(
+      child_id, GetNextPrerenderID(), pending_url, kDefaultRelTypes,
+      content::Referrer(), kSize, route_id);
   const int second_prerender_id = last_prerender_id();
 
   EXPECT_FALSE(IsEmptyPrerenderLinkManager());
diff --git a/chrome/chrome_common.gypi b/chrome/chrome_common.gypi
index e6ce973..1f0d3f1 100644
--- a/chrome/chrome_common.gypi
+++ b/chrome/chrome_common.gypi
@@ -327,6 +327,7 @@
         'common/pepper_permission_util.h',
         'common/pref_names_util.cc',
         'common/pref_names_util.h',
+        'common/prerender_types.h',
         'common/print_messages.cc',
         'common/print_messages.h',
         'common/profiling.cc',
diff --git a/chrome/common/prerender_messages.h b/chrome/common/prerender_messages.h
index 2b0310c..21ce045 100644
--- a/chrome/common/prerender_messages.h
+++ b/chrome/common/prerender_messages.h
@@ -18,11 +18,16 @@
 // These are messages sent from the renderer to the browser in
 // relation to <link rel=prerender> elements.
 
+IPC_STRUCT_BEGIN(PrerenderAttributes)
+  IPC_STRUCT_MEMBER(GURL, url)
+  IPC_STRUCT_MEMBER(uint32, rel_types)
+IPC_STRUCT_END()
+
 // Notifies of the insertion of a <link rel=prerender> element in the
 // document.
 IPC_MESSAGE_CONTROL5(PrerenderHostMsg_AddLinkRelPrerender,
                      int /* prerender_id, assigned by WebPrerendererClient */,
-                     GURL /* url */,
+                     PrerenderAttributes,
                      content::Referrer,
                      gfx::Size,
                      int /* render_view_route_id of launcher */)
diff --git a/chrome/common/prerender_types.h b/chrome/common/prerender_types.h
new file mode 100644
index 0000000..3ed3dd0
--- /dev/null
+++ b/chrome/common/prerender_types.h
@@ -0,0 +1,19 @@
+// Copyright 2014 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.
+
+#ifndef CHROME_COMMON_PRERENDER_TYPES_H_
+#define CHROME_COMMON_PRERENDER_TYPES_H_
+
+namespace prerender {
+
+// PrerenderRelType is a bitfield since multiple rel attributes can be set
+// on the same link. Must be the same as blink::WebPrerenderRelType.
+enum PrerenderRelType {
+  PrerenderRelTypePrerender = 0x1,
+  PrerenderRelTypeNext = 0x2,
+};
+
+}  // namespace prerender
+
+#endif  // CHROME_COMMON_PRERENDER_TYPES_H_
diff --git a/chrome/renderer/prerender/prerender_dispatcher.cc b/chrome/renderer/prerender/prerender_dispatcher.cc
index a787a70..31e23cf 100644
--- a/chrome/renderer/prerender/prerender_dispatcher.cc
+++ b/chrome/renderer/prerender/prerender_dispatcher.cc
@@ -6,6 +6,7 @@
 
 #include "base/logging.h"
 #include "chrome/common/prerender_messages.h"
+#include "chrome/common/prerender_types.h"
 #include "chrome/renderer/prerender/prerender_extra_data.h"
 #include "content/public/common/referrer.h"
 #include "content/public/renderer/render_thread.h"
@@ -117,8 +118,12 @@ void PrerenderDispatcher::add(const WebPrerender& prerender) {
 
   prerenders_[extra_data.prerender_id()] = prerender;
 
+  PrerenderAttributes attributes;
+  attributes.url = GURL(prerender.url());
+  attributes.rel_types = prerender.relTypes();
+
   content::RenderThread::Get()->Send(new PrerenderHostMsg_AddLinkRelPrerender(
-      extra_data.prerender_id(), GURL(prerender.url()),
+      extra_data.prerender_id(), attributes,
       content::Referrer(GURL(prerender.referrer()),
                         prerender.referrerPolicy()),
       extra_data.size(), extra_data.render_view_route_id()));