Revert "[BrowserSwitcher] Deflake BrowserSwitcherServiceTest"

This reverts commit 54aa10ad.

Reason for revert: crbug.com/1073010

Original change's description:
> [BrowserSwitcher] Deflake BrowserSwitcherServiceTest
> 
> Previously, the tests waited for action_timeout(), to wait for LBS to
> load the rules and write some files. As expected, this is fairly flaky,
> and it slows down the tests.
> 
> Now, `BrowserSwitcherService' exposes a new event for testing, which
> fires once LBS has loaded the rules. This should reduce flakes by
> listening for the event instead of using an unreliable timeout.
> 
> Also rewrote some tests in a synchronous style, which improves
> readability.
> 
> Bug: 1044619, 1070400
> Change-Id: If1a2093cfe3bface73a46896ff2bc95b80ab2f2e
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2152885
> Commit-Queue: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
> Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#760531}

TBR=pastarmovj@chromium.org,nicolaso@chromium.org

Change-Id: If573be05ce1a3d4a34449bd6038f16129cb4d1fa
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1044619, 1070400
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2159313Reviewed-by: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
Commit-Queue: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760985}

chrome/browser/browser_switcher/browser_switcher_service.cc

@@ -239,11 +239,6 @@ void BrowserSwitcherService::Init() {
   StartDownload(fetch_delay());
 }
 
-void BrowserSwitcherService::OnAllRulesetsLoadedForTesting(
-    base::OnceCallback<void()> cb) {
-  all_rulesets_loaded_callback_for_testing_ = std::move(cb);
-}
-
 void BrowserSwitcherService::StartDownload(base::TimeDelta delay) {
   // This destroys the previous XmlDownloader, which cancels any scheduled
   // refresh operations.
@@ -324,8 +319,6 @@ void BrowserSwitcherService::LoadRulesFromPrefs() {
 
 void BrowserSwitcherService::OnAllRulesetsParsed() {
   callback_list_.Notify(this);
-  if (all_rulesets_loaded_callback_for_testing_)
-    std::move(all_rulesets_loaded_callback_for_testing_).Run();
 }
 
 std::unique_ptr<BrowserSwitcherService::CallbackSubscription>

chrome/browser/browser_switcher/browser_switcher_service.h

@@ -124,8 +124,6 @@ class BrowserSwitcherService : public KeyedService {
   explicit BrowserSwitcherService(Profile* profile);
   ~BrowserSwitcherService() override;
 
-  virtual void Init();
-
   // KeyedService:
   void Shutdown() override;
 
@@ -151,10 +149,7 @@ class BrowserSwitcherService : public KeyedService {
   // happens.
   virtual void LoadRulesFromPrefs();
 
-  // Called after all XML rulesets finished downloading, and the rules are
-  // applied. The XML is downloaded asynchronously, so browser tests use this
-  // event to check that they applied correctly.
-  void OnAllRulesetsLoadedForTesting(base::OnceCallback<void()> callback);
+  void Init();
 
  protected:
   virtual void OnAllRulesetsParsed();
@@ -199,8 +194,6 @@ class BrowserSwitcherService : public KeyedService {
   // CallbackList for OnAllRulesetsParsed() listeners.
   base::CallbackList<AllRulesetsParsedCallbackSignature> callback_list_;
 
-  base::OnceCallback<void()> all_rulesets_loaded_callback_for_testing_;
-
   // Per-profile helpers.
   std::unique_ptr<AlternativeBrowserDriver> driver_;
   std::unique_ptr<BrowserSwitcherSitelist> sitelist_;

chrome/browser/browser_switcher/browser_switcher_service_win.cc

@@ -27,8 +27,6 @@
 #include "chrome/browser/browser_switcher/browser_switcher_sitelist.h"
 #include "chrome/browser/browser_switcher/ieem_sitelist_parser.h"
 #include "chrome/browser/profiles/profile.h"
-#include "content/public/browser/browser_task_traits.h"
-#include "content/public/browser/browser_thread.h"
 #include "extensions/browser/extension_registry.h"
 
 namespace browser_switcher {
@@ -138,7 +136,9 @@ BrowserSwitcherServiceWin::BrowserSwitcherServiceWin(
       cache_dir_for_testing_(std::move(cache_dir_for_testing)),
       sequenced_task_runner_(base::ThreadPool::CreateSequencedTaskRunner(
           {base::MayBlock(), base::TaskPriority::BEST_EFFORT,
-           base::TaskShutdownBehavior::BLOCK_SHUTDOWN})) {}
+           base::TaskShutdownBehavior::BLOCK_SHUTDOWN})) {
+  UpdateAllCacheFiles();
+}
 
 BrowserSwitcherServiceWin::~BrowserSwitcherServiceWin() = default;
 
@@ -166,16 +166,14 @@ std::vector<RulesetSource> BrowserSwitcherServiceWin::GetRulesetSources() {
   return sources;
 }
 
-void BrowserSwitcherServiceWin::Init() {
-  BrowserSwitcherService::Init();
-  UpdateAllCacheFiles();
-}
-
 void BrowserSwitcherServiceWin::LoadRulesFromPrefs() {
   BrowserSwitcherService::LoadRulesFromPrefs();
   if (prefs().UseIeSitelist())
     sitelist()->SetIeemSitelist(
         ParsedXml(prefs().GetCachedIeemSitelist(), base::nullopt));
+  if (!prefs().IsEnabled())
+    return;
+  SavePrefsToFile();
 }
 
 base::FilePath BrowserSwitcherServiceWin::GetCacheDir() {
@@ -234,51 +232,25 @@ void BrowserSwitcherServiceWin::OnIeemSitelistParsed(ParsedXml xml) {
   }
 }
 
-void BrowserSwitcherServiceWin::CacheFileUpdated() {
-  if (cache_file_updated_callback_for_testing_)
-    std::move(cache_file_updated_callback_for_testing_).Run();
-}
-
-void BrowserSwitcherServiceWin::SitelistCacheFileUpdated() {
-  if (sitelist_cache_file_updated_callback_for_testing_)
-    std::move(sitelist_cache_file_updated_callback_for_testing_).Run();
-}
-
-void BrowserSwitcherServiceWin::OnCacheFileUpdatedForTesting(
-    base::OnceClosure cb) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  cache_file_updated_callback_for_testing_ = std::move(cb);
-}
-
-void BrowserSwitcherServiceWin::OnSitelistCacheFileUpdatedForTesting(
-    base::OnceClosure cb) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  sitelist_cache_file_updated_callback_for_testing_ = std::move(cb);
-}
-
-void BrowserSwitcherServiceWin::DeletePrefsFile() {
+void BrowserSwitcherServiceWin::SavePrefsToFile() {
+  DCHECK(prefs().IsEnabled());
   base::FilePath path = GetCacheDir();
   if (path.empty())
     return;
   path = path.AppendASCII("cache.dat");
-  sequenced_task_runner_->PostTaskAndReply(
-      FROM_HERE, base::BindOnce(&RemoveFile, std::move(path)),
-      base::BindOnce(&BrowserSwitcherServiceWin::CacheFileUpdated,
-                     base::Unretained(this)));
+  sequenced_task_runner_->PostTask(
+      FROM_HERE,
+      base::BindOnce(&SaveDataToFile, SerializeCacheFile(prefs(), sitelist()),
+                     std::move(path)));
 }
 
-void BrowserSwitcherServiceWin::SavePrefsToFile() {
-  DCHECK(prefs().IsEnabled());
+void BrowserSwitcherServiceWin::DeletePrefsFile() {
   base::FilePath path = GetCacheDir();
   if (path.empty())
     return;
   path = path.AppendASCII("cache.dat");
-  sequenced_task_runner_->PostTaskAndReply(
-      FROM_HERE,
-      base::BindOnce(&SaveDataToFile, SerializeCacheFile(prefs(), sitelist()),
-                     std::move(path)),
-      base::BindOnce(&BrowserSwitcherServiceWin::CacheFileUpdated,
-                     base::Unretained(this)));
+  sequenced_task_runner_->PostTask(
+      FROM_HERE, base::BindOnce(&RemoveFile, std::move(path)));
 }
 
 void BrowserSwitcherServiceWin::DeleteSitelistCacheFile() {
@@ -286,10 +258,8 @@ void BrowserSwitcherServiceWin::DeleteSitelistCacheFile() {
   if (path.empty())
     return;
   path = path.AppendASCII("sitelistcache.dat");
-  sequenced_task_runner_->PostTaskAndReply(
-      FROM_HERE, base::BindOnce(&RemoveFile, std::move(path)),
-      base::BindOnce(&BrowserSwitcherServiceWin::SitelistCacheFileUpdated,
-                     base::Unretained(this)));
+  sequenced_task_runner_->PostTask(
+      FROM_HERE, base::BindOnce(&RemoveFile, std::move(path)));
 }
 
 void BrowserSwitcherServiceWin::UpdateAllCacheFiles() {

chrome/browser/browser_switcher/browser_switcher_service_win.h

@@ -22,8 +22,6 @@ class BrowserSwitcherServiceWin : public BrowserSwitcherService {
       base::FilePath cache_dir_for_testing = base::FilePath());
   ~BrowserSwitcherServiceWin() override;
 
-  void Init() override;
-
   static void SetIeemSitelistUrlForTesting(const std::string& url);
 
   // BrowserSwitcherService:
@@ -31,9 +29,6 @@ class BrowserSwitcherServiceWin : public BrowserSwitcherService {
 
   void LoadRulesFromPrefs() override;
 
-  void OnCacheFileUpdatedForTesting(base::OnceClosure cb);
-  void OnSitelistCacheFileUpdatedForTesting(base::OnceClosure cb);
-
  protected:
   // BrowserSwitcherService:
   void OnAllRulesetsParsed() override;
@@ -64,16 +59,11 @@ class BrowserSwitcherServiceWin : public BrowserSwitcherService {
   // extension, or from a previous Chrome version. Called during initialization.
   void DeleteSitelistCacheFile();
 
-  void CacheFileUpdated();
-  void SitelistCacheFileUpdated();
-
   // Updates or cleans up cache.dat and sitelistcache.dat, based on whether
   // BrowserSwitcher is enabled or disabled.
   void UpdateAllCacheFiles();
 
   base::FilePath cache_dir_for_testing_;
-  base::OnceClosure cache_file_updated_callback_for_testing_;
-  base::OnceClosure sitelist_cache_file_updated_callback_for_testing_;
 
   scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner_;