Make PrerenderHandle an observer of PrerenderContents.

chrome/browser/prerender/prerender_unittest.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 "base/command_line.h"
 #include "base/memory/scoped_vector.h"
 #include "base/message_loop.h"
 #include "base/stringprintf.h"
 #include "base/time.h"
 #include "chrome/browser/prerender/prerender_contents.h"
@@ skipping 631 matching lines @@
   DummyPrerenderContents* pending_prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           pending_url,
           ORIGIN_GWS_PRERENDER,
           FINAL_STATUS_USED);
   scoped_ptr<PrerenderHandle> pending_prerender_handle(
       prerender_manager()->AddPrerenderFromLinkRelPrerender(
           child_id, route_id, pending_url,
           Referrer(url, WebKit::WebReferrerPolicyDefault), kSize));
   CHECK(pending_prerender_handle.get());
-  EXPECT_TRUE(pending_prerender_handle->IsValid());
-  EXPECT_TRUE(pending_prerender_handle->IsPending());
+  EXPECT_FALSE(pending_prerender_handle->IsValid());
 
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
 
-  EXPECT_FALSE(pending_prerender_handle->IsPending());
+  EXPECT_TRUE(pending_prerender_handle->IsValid());
   ASSERT_EQ(pending_prerender_contents,
             prerender_manager()->FindAndUseEntry(pending_url));
 }
 
 TEST_F(PrerenderTest, InvalidPendingPrerenderTest) {
   GURL url("http://www.google.com/");
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url,
           FINAL_STATUS_USED);
@@ skipping 10 matching lines @@
 
   prerender_manager()->CreateNextPrerenderContents(
       pending_url,
       ORIGIN_GWS_PRERENDER,
       FINAL_STATUS_UNSUPPORTED_SCHEME);
   scoped_ptr<PrerenderHandle> pending_prerender_handle(
       prerender_manager()->AddPrerenderFromLinkRelPrerender(
           child_id, route_id, pending_url,
           Referrer(url, WebKit::WebReferrerPolicyDefault), kSize));
   DCHECK(pending_prerender_handle.get());
-  EXPECT_TRUE(pending_prerender_handle->IsValid());
-  EXPECT_TRUE(pending_prerender_handle->IsPending());
+  EXPECT_FALSE(pending_prerender_handle->IsValid());
 
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
 
   EXPECT_FALSE(pending_prerender_handle->IsValid());
-  EXPECT_FALSE(pending_prerender_handle->IsPending());
 }
 
 TEST_F(PrerenderTest, CancelPendingPrerenderTest) {
   GURL url("http://www.google.com/");
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url,
           FINAL_STATUS_USED);
   EXPECT_TRUE(AddSimplePrerender(url));
 
   int child_id;
   int route_id;
   ASSERT_TRUE(prerender_contents->GetChildId(&child_id));
   ASSERT_TRUE(prerender_contents->GetRouteId(&route_id));
 
   GURL pending_url("http://news.google.com/");
 
   scoped_ptr<PrerenderHandle> pending_prerender_handle(
       prerender_manager()->AddPrerenderFromLinkRelPrerender(
           child_id, route_id, pending_url,
           Referrer(url, WebKit::WebReferrerPolicyDefault), kSize));
   CHECK(pending_prerender_handle.get());
-  EXPECT_TRUE(pending_prerender_handle->IsValid());
-  EXPECT_TRUE(pending_prerender_handle->IsPending());
+  EXPECT_FALSE(pending_prerender_handle->IsValid());
 
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
 
   pending_prerender_handle->OnCancel();
-  EXPECT_FALSE(pending_prerender_handle->IsValid());
+  EXPECT_FALSE(pending_prerender_handle->IsPrerendering());
 
   ASSERT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
 }
 
 // Tests that a PrerenderManager created for a browser session in the control
 // group works as expected.
 TEST_F(PrerenderTest, ControlGroup) {
   RestorePrerenderMode restore_prerender_mode;
   PrerenderManager::SetMode(
       PrerenderManager::PRERENDER_MODE_EXPERIMENT_CONTROL_GROUP);
@@ skipping 96 matching lines @@
   EXPECT_TRUE(AddSimplePrerender(url));
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   // Force the creation of a match complete dummy.
   DummyPrerenderContents* duplicate_prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(url,
                                                        FINAL_STATUS_CANCELLED);
   ASSERT_EQ(prerender_contents, prerender_manager()->FindEntry(url));
   prerender_contents->Destroy(FINAL_STATUS_JAVASCRIPT_ALERT);
   ASSERT_EQ(duplicate_prerender_contents, prerender_manager()->FindEntry(url));
 
+  // Surprisingly, OnCancelPrerender isn't expected to do anything because the
+  // PrerenderLinkManager has already removed this prerender.

[mmenke, 2012/12/07 16:46:08]

Doesn't this mess up book keeping?  If the prerender is cancelled, we want to
delete the dummy...

[gavinp, 2012/12/10 17:55:10]

But the PrerenderStop event was sent, and that removed it from the map. The
bookkeeping is already quite messed up once we start sending events down...

The fix is architecturally pretty nasty:
PrerenderManager::MoveEntryToPendingDelete needs to reach into the handle to
reinsert an entry? Or perhaps squash the event through an output parameter?

   prerender_link_manager()->OnCancelPrerender(kDefaultChildId,
                                               last_prerender_id());
+  ASSERT_EQ(duplicate_prerender_contents, prerender_manager()->FindEntry(url));
+
+  // But the PrerenderContents will exist, albiet with no handle.
+  duplicate_prerender_contents->Destroy(FINAL_STATUS_CANCELLED);
   DummyPrerenderContents* null = NULL;
   ASSERT_EQ(null, prerender_manager()->FindEntry(url));
 }
 
-
 // Tests that the prerender manager matches include the fragment.
 TEST_F(PrerenderTest, FragmentMatchesTest) {
   GURL fragment_url("http://www.google.com/#test");
 
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(fragment_url,
                                                        FINAL_STATUS_USED);
   EXPECT_TRUE(AddSimplePrerender(fragment_url));
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   ASSERT_EQ(prerender_contents,
@@ skipping 120 matching lines @@
 
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   EXPECT_FALSE(prerender_contents->prerendering_has_been_cancelled());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindEntry(url));
   EXPECT_FALSE(IsEmptyPrerenderLinkManager());
   prerender_link_manager()->OnAbandonPrerender(kDefaultChildId,
                                                last_prerender_id());
 
   EXPECT_FALSE(prerender_contents->prerendering_has_been_cancelled());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
-  EXPECT_TRUE(IsEmptyPrerenderLinkManager());
 }
 
 TEST_F(PrerenderTest, LinkManagerCancelTwice) {
   EXPECT_TRUE(IsEmptyPrerenderLinkManager());
   GURL url("http://www.myexample.com");
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_CANCELLED);
 
   EXPECT_TRUE(AddSimplePrerender(url));
@@ skipping 109 matching lines @@
   EXPECT_FALSE(prerender_contents->prerendering_has_been_cancelled());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindEntry(url));
   prerender_link_manager()->OnAbandonPrerender(kDefaultChildId,
                                                first_prerender_id);
 
   EXPECT_FALSE(prerender_contents->prerendering_has_been_cancelled());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindEntry(url));
   prerender_link_manager()->OnAbandonPrerender(kDefaultChildId,
                                                second_prerender_id);
 
-  EXPECT_TRUE(IsEmptyPrerenderLinkManager());
   EXPECT_FALSE(prerender_contents->prerendering_has_been_cancelled());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
 }
 
 // TODO(gavinp): After abandon shortens the expire time on a Prerender,
 // add a series of tests testing advancing the time by either the abandon
 // or normal expire, and verifying the expected behaviour with groups
 // of links.
 TEST_F(PrerenderTest, LinkManagerExpireThenCancel) {
   EXPECT_TRUE(IsEmptyPrerenderLinkManager());
@@ skipping 35 matching lines @@
       prerender_manager()->config().time_to_live + TimeDelta::FromSeconds(1));
   DummyPrerenderContents* null = NULL;
   ASSERT_EQ(null, prerender_manager()->FindEntry(url));
   DummyPrerenderContents* second_prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_USED);
   EXPECT_TRUE(AddSimplePrerender(url));
   EXPECT_TRUE(second_prerender_contents->prerendering_has_started());
   ASSERT_EQ(second_prerender_contents,
             prerender_manager()->FindAndUseEntry(url));
-  // The PrerenderLinkManager is not empty since we never removed the first
-  // prerender.
-  EXPECT_FALSE(IsEmptyPrerenderLinkManager());
 }
 
 TEST_F(PrerenderTest, LinkManagerCancelThenAddAgain) {
   EXPECT_TRUE(IsEmptyPrerenderLinkManager());
   GURL url("http://www.myexample.com");
   DummyPrerenderContents* first_prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_CANCELLED);
   EXPECT_TRUE(AddSimplePrerender(url));
   EXPECT_TRUE(first_prerender_contents->prerendering_has_started());
   EXPECT_FALSE(first_prerender_contents->prerendering_has_been_cancelled());
   ASSERT_EQ(first_prerender_contents, prerender_manager()->FindEntry(url));
   prerender_link_manager()->OnCancelPrerender(kDefaultChildId,
                                               last_prerender_id());
   EXPECT_TRUE(IsEmptyPrerenderLinkManager());
   EXPECT_TRUE(first_prerender_contents->prerendering_has_been_cancelled());
   DummyPrerenderContents* null = NULL;
   ASSERT_EQ(null, prerender_manager()->FindEntry(url));
   DummyPrerenderContents* second_prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_USED);
   EXPECT_TRUE(AddSimplePrerender(url));
   EXPECT_TRUE(second_prerender_contents->prerendering_has_started());
   ASSERT_EQ(second_prerender_contents,
             prerender_manager()->FindAndUseEntry(url));
-  EXPECT_FALSE(IsEmptyPrerenderLinkManager());
 }
 
 }  // namespace prerender