Don't clear the net predictors prefs on startup

chrome/browser/net/predictor_browsertest.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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
 #include <set>
 
 #include "base/base64.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/run_loop.h"
 #include "base/stl_util.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
+#include "chrome/browser/browsing_data/browsing_data_helper.h"
+#include "chrome/browser/browsing_data/browsing_data_remover.h"
+#include "chrome/browser/browsing_data/browsing_data_remover_factory.h"
 #include "chrome/browser/net/predictor.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "components/prefs/pref_service.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/test/browser_test_utils.h"
@@ skipping 1307 matching lines @@
   // preconnects to go through.
   // Note that ceil(2 + .33) + 1 = 4.
   cross_site_connection_listener_->WaitForAcceptedConnectionsOnUI(4u);
 }
 
 IN_PROC_BROWSER_TEST_F(PredictorBrowserTest,
                        PRE_ShutdownStartupCyclePreresolve) {
   // Prepare state that will be serialized on this shut-down and read on next
   // start-up. Ensure preresolution over preconnection.
   LearnAboutInitialNavigation(startup_url_);
-  // The target url will have a expected connection count of 2 after this call.
+  // The target URL will have an expected connection count of 2 after this call.
   InstallPredictorObserver(referring_url_, target_url_);
   LearnFromNavigation(referring_url_, target_url_);
 
   // In order to reduce the expected connection count < .8, issue predictions 3
   // times. 2 * .66^3 ~= .58.
   PrepareFrameSubresources(referring_url_);
   PrepareFrameSubresources(referring_url_);
   PrepareFrameSubresources(referring_url_);
 }
 
 IN_PROC_BROWSER_TEST_F(PredictorBrowserTest, ShutdownStartupCyclePreresolve) {
-  // Make sure that the Preferences file is actually wiped of all DNS prefetch
-  // related data after start-up.
-  std::string cleared_startup_list;
-  std::string cleared_referral_list;
-  GetListFromPrefsAsString(prefs::kDnsPrefetchingStartupList,
-                           &cleared_startup_list);
-  GetListFromPrefsAsString(prefs::kDnsPrefetchingHostReferralList,
-                           &cleared_referral_list);
-
-  EXPECT_THAT(cleared_startup_list, Not(HasSubstr(startup_url_.host())));
-  EXPECT_THAT(cleared_referral_list, Not(HasSubstr(referring_url_.host())));
-  EXPECT_THAT(cleared_referral_list, Not(HasSubstr(target_url_.host())));
-
-  // But also make sure this data has been first loaded into the Predictor, by
-  // inspecting that the Predictor starts making the expected hostname requests.
+  // Make sure this data has been loaded into the Predictor, by inspecting that
+  // the Predictor starts making the expected hostname requests.
   PrepareFrameSubresources(referring_url_);
   observer()->WaitUntilHostLookedUp(target_url_);
 
   // Verify that both urls were requested by the predictor. Note that the
   // startup URL may be requested before the observer attaches itself.
   ExpectUrlRequestedFromPredictor(startup_url_);
   EXPECT_FALSE(observer()->HostFound(target_url_));
 }
 
+IN_PROC_BROWSER_TEST_F(PredictorBrowserTest, PRE_ClearData) {
+  // The target url will have a expected connection count of 2 after this call.
+  InstallPredictorObserver(referring_url_, target_url_);
+  LearnFromNavigation(referring_url_, target_url_);
+}
+
+// Ensure predictive data is cleared when the history is cleared.
+IN_PROC_BROWSER_TEST_F(PredictorBrowserTest, ClearData) {
+  std::string cleared_startup_list;
+  std::string cleared_referral_list;
+
+  // The pref should persist after startup.
+  GetListFromPrefsAsString(prefs::kDnsPrefetchingStartupList,
+                           &cleared_startup_list);
+  GetListFromPrefsAsString(prefs::kDnsPrefetchingHostReferralList,
+                           &cleared_referral_list);
+  EXPECT_THAT(cleared_referral_list, HasSubstr(referring_url_.host()));
+  EXPECT_THAT(cleared_referral_list, HasSubstr(target_url_.host()));
+
+  // Clear cache which should clear all prefs.
+  BrowsingDataRemover* remover =
+      BrowsingDataRemoverFactory::GetForBrowserContext(browser()->profile());
+  remover->Remove(BrowsingDataRemover::Unbounded(),
+                  BrowsingDataRemover::REMOVE_HISTORY,
+                  BrowsingDataHelper::UNPROTECTED_WEB);
+
+  GetListFromPrefsAsString(prefs::kDnsPrefetchingStartupList,
+                           &cleared_startup_list);
+  GetListFromPrefsAsString(prefs::kDnsPrefetchingHostReferralList,
+                           &cleared_referral_list);
+  EXPECT_THAT(cleared_referral_list, Not(HasSubstr(referring_url_.host())));
+  EXPECT_THAT(cleared_referral_list, Not(HasSubstr(target_url_.host())));
+}
+
 // The predictor should not evict recently used (navigated to) referrers.
 IN_PROC_BROWSER_TEST_F(PredictorBrowserTest, DoNotEvictRecentlyUsed) {
   observer()->SetStrict(false);
   for (int i = 0; i < Predictor::kMaxReferrers; ++i) {
     LearnFromNavigation(
         GURL(base::StringPrintf("http://www.source%d.test", i)),
         GURL(base::StringPrintf("http://www.target%d.test", i)));
   }
   ui_test_utils::NavigateToURL(browser(), GURL("http://source0.test"));
 
@@ skipping 129 matching lines @@
   // Second navigation to content with an img.
   std::string img_content =
       "<img src=\"" + preconnect_url.spec() + "test.gif\">";
   NavigateToDataURLWithContent(img_content);
   connection_listener_->WaitUntilFirstConnectionRead();
   EXPECT_EQ(2u, connection_listener_->GetAcceptedSocketCount());
   EXPECT_EQ(1u, connection_listener_->GetReadSocketCount());
 }
 
 }  // namespace chrome_browser_net