Avoid doing periodic prerender cleanup when there are no contents.

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 <map>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/format_macros.h"
 #include "base/memory/scoped_vector.h"
@@ skipping 898 matching lines @@
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_USED);
   EXPECT_TRUE(AddSimplePrerender(url));
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
 }
 
 // Tests that our PPLT dummy prerender gets created properly.
 TEST_F(PrerenderTest, PPLTDummy) {
+  RestorePrerenderMode restore_prerender_mode;
+  PrerenderManager::SetMode(
+      PrerenderManager::PRERENDER_MODE_EXPERIMENT_MATCH_COMPLETE_GROUP);
+
   GURL url("http://www.google.com/");
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_UNSUPPORTED_SCHEME);
   EXPECT_TRUE(AddSimplePrerender(url));
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   EXPECT_FALSE(IsEmptyPrerenderLinkManager());
 
   DummyPrerenderContents* pplt_dummy_contents =
       prerender_manager()->CreateNextPrerenderContents(url,
                                                        FINAL_STATUS_USED);
   GURL ftp_url("ftp://ftp.google.com/");
   // Adding this ftp URL will force the expected unsupported scheme error.
   prerender_contents->AddAliasURL(ftp_url);
   EXPECT_FALSE(IsEmptyPrerenderLinkManager());
 
   ASSERT_EQ(pplt_dummy_contents, prerender_manager()->FindAndUseEntry(url));
   EXPECT_TRUE(IsEmptyPrerenderLinkManager());
 }
 
 // Tests that our PPLT dummy prerender gets created properly, even
 // when navigating to a page that has been recently navigated to.
 TEST_F(PrerenderTest, RecentlyVisitedPPLTDummy) {
+  RestorePrerenderMode restore_prerender_mode;
+  PrerenderManager::SetMode(
+      PrerenderManager::PRERENDER_MODE_EXPERIMENT_MATCH_COMPLETE_GROUP);
+
   GURL url("http://www.google.com/");
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_UNSUPPORTED_SCHEME);
   EXPECT_TRUE(AddSimplePrerender(url));
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
 
   DummyPrerenderContents* pplt_dummy_contents =
       prerender_manager()->CreateNextPrerenderContents(url,
                                                        FINAL_STATUS_USED);
   prerender_manager()->RecordNavigation(url);
   GURL ftp_url("ftp://ftp.google.com/");
   prerender_contents->AddAliasURL(ftp_url);
 
   ASSERT_EQ(pplt_dummy_contents, prerender_manager()->FindAndUseEntry(url));
 }
 
 TEST_F(PrerenderTest, PPLTLateCancel) {
+  RestorePrerenderMode restore_prerender_mode;
+  PrerenderManager::SetMode(
+      PrerenderManager::PRERENDER_MODE_EXPERIMENT_MATCH_COMPLETE_GROUP);
+
   GURL url("http://www.google.com");
   DummyPrerenderContents* prerender_contents =
       prerender_manager()->CreateNextPrerenderContents(
           url, FINAL_STATUS_JAVASCRIPT_ALERT);
   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);
@@ skipping 601 matching lines @@
   CHECK(prerender_handle.get());
   EXPECT_TRUE(prerender_handle->IsPrerendering());
   EXPECT_TRUE(prerender_contents->prerendering_has_started());
   EXPECT_EQ(prerender_contents, prerender_handle->contents());
   EXPECT_EQ(ORIGIN_INSTANT, prerender_handle->contents()->origin());
   ASSERT_EQ(prerender_contents, prerender_manager()->FindAndUseEntry(url));
   EXPECT_FALSE(prerender_handle->IsPrerendering());
 }
 
 }  // namespace prerender