Don't assume UI/DB threads unnecessarily.

Some code that currently assumes it's running on the UI or DB threads can simply
use "the current thread" or "the background thread" or similar.

Bug: 689520
Change-Id: Ide84528d7abea223939bef247c1f4d9c47bb8752
Reviewed-on: https://chromium-review.googlesource.com/578144
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Vaclav Brozek <vabr@chromium.org>
Reviewed-by: Selim Gurun <sgurun@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488419}

android_webview/browser/aw_form_database_service.cc

@@ -9,6 +9,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/task_scheduler/post_task.h"
 #include "base/threading/thread_restrictions.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "components/autofill/core/browser/webdata/autofill_table.h"
 #include "components/webdata/common/webdata_constants.h"
 #include "content/public/browser/browser_thread.h"
@@ -34,16 +35,15 @@ AwFormDatabaseService::AwFormDatabaseService(const base::FilePath path)
       has_form_data_completion_(
           base::WaitableEvent::ResetPolicy::AUTOMATIC,
           base::WaitableEvent::InitialState::NOT_SIGNALED) {
-  CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  auto ui_thread = base::ThreadTaskRunnerHandle::Get();
   web_database_ = new WebDatabaseService(
-      path.Append(kWebDataFilename),
-      BrowserThread::GetTaskRunnerForThread(BrowserThread::UI),
+      path.Append(kWebDataFilename), ui_thread,
       BrowserThread::GetTaskRunnerForThread(BrowserThread::DB));
   web_database_->AddTable(base::WrapUnique(new autofill::AutofillTable));
   web_database_->LoadDatabase();
 
   autofill_data_ = new autofill::AutofillWebDataService(
-      web_database_, BrowserThread::GetTaskRunnerForThread(BrowserThread::UI),
+      web_database_, ui_thread,
       BrowserThread::GetTaskRunnerForThread(BrowserThread::DB),
       base::Bind(&DatabaseErrorCallback));
   autofill_data_->Init();
@@ -54,7 +54,6 @@ AwFormDatabaseService::~AwFormDatabaseService() {
 }
 
 void AwFormDatabaseService::Shutdown() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
   // TODO(sgurun) we don't run into this logic right now,
   // but if we do, then we need to implement cancellation
   // of pending queries.

chrome/browser/password_manager/password_store_win.cc

@@ -23,10 +23,8 @@
 #include "components/password_manager/core/browser/password_manager.h"
 #include "components/password_manager/core/browser/password_manager_metrics_util.h"
 #include "components/password_manager/core/browser/webdata/password_web_data_service_win.h"
-#include "content/public/browser/browser_thread.h"
 
 using autofill::PasswordForm;
-using content::BrowserThread;
 using password_manager::PasswordStore;
 using password_manager::PasswordStoreDefault;
 
@@ -86,7 +84,8 @@ class PasswordStoreWin::DBHandler : public WebDataServiceConsumer {
 };
 
 PasswordStoreWin::DBHandler::~DBHandler() {
-  DCHECK_CURRENTLY_ON(BrowserThread::DB);
+  DCHECK(
+      password_store_->GetBackgroundTaskRunner()->RunsTasksInCurrentSequence());
   for (PendingRequestMap::const_iterator i = pending_requests_.begin();
        i != pending_requests_.end();
        ++i) {
@@ -97,7 +96,8 @@ PasswordStoreWin::DBHandler::~DBHandler() {
 void PasswordStoreWin::DBHandler::GetIE7Login(
     const PasswordStore::FormDigest& form,
     const ResultCallback& result_callback) {
-  DCHECK_CURRENTLY_ON(BrowserThread::DB);
+  DCHECK(
+      password_store_->GetBackgroundTaskRunner()->RunsTasksInCurrentSequence());
   IE7PasswordInfo info;
   info.url_hash =
       ie7_password::GetUrlHash(base::UTF8ToWide(form.origin.spec()));
@@ -111,7 +111,8 @@ std::vector<std::unique_ptr<PasswordForm>>
 PasswordStoreWin::DBHandler::GetIE7Results(
     const WDTypedResult* result,
     const PasswordStore::FormDigest& form) {
-  DCHECK_CURRENTLY_ON(BrowserThread::DB);
+  DCHECK(
+      password_store_->GetBackgroundTaskRunner()->RunsTasksInCurrentSequence());
   std::vector<std::unique_ptr<PasswordForm>> matched_forms;
   const WDResult<IE7PasswordInfo>* r =
       static_cast<const WDResult<IE7PasswordInfo>*>(result);
@@ -155,7 +156,8 @@ void PasswordStoreWin::DBHandler::OnWebDataServiceRequestDone(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "422460 PasswordStoreWin::DBHandler::OnWebDataServiceRequestDone"));
 
-  DCHECK_CURRENTLY_ON(BrowserThread::DB);
+  DCHECK(
+      password_store_->GetBackgroundTaskRunner()->RunsTasksInCurrentSequence());
 
   PendingRequestMap::iterator i = pending_requests_.find(handle);
   DCHECK(i != pending_requests_.end());
@@ -197,14 +199,13 @@ PasswordStoreWin::~PasswordStoreWin() {
 }
 
 void PasswordStoreWin::ShutdownOnDBThread() {
-  DCHECK_CURRENTLY_ON(BrowserThread::DB);
+  DCHECK(GetBackgroundTaskRunner()->RunsTasksInCurrentSequence());
   db_handler_.reset();
 }
 
 void PasswordStoreWin::ShutdownOnUIThread() {
-  BrowserThread::PostTask(
-      BrowserThread::DB, FROM_HERE,
-      base::Bind(&PasswordStoreWin::ShutdownOnDBThread, this));
+  GetBackgroundTaskRunner()->PostTask(
+      FROM_HERE, base::Bind(&PasswordStoreWin::ShutdownOnDBThread, this));
   PasswordStoreDefault::ShutdownOnUIThread();
 }
 

chrome/browser/password_manager/password_store_win_unittest.cc

@@ -22,6 +22,7 @@
 #include "base/synchronization/waitable_event.h"
 #include "base/test/histogram_tester.h"
 #include "base/threading/sequenced_task_runner_handle.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "chrome/test/base/testing_profile.h"
 #include "components/os_crypt/ie7_password_win.h"
@@ -31,8 +32,6 @@
 #include "components/password_manager/core/browser/password_store_consumer.h"
 #include "components/password_manager/core/browser/webdata/logins_table.h"
 #include "components/password_manager/core/browser/webdata/password_web_data_service_win.h"
-#include "components/password_manager/core/common/password_manager_pref_names.h"
-#include "components/prefs/pref_service.h"
 #include "components/webdata/common/web_database_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/test/test_browser_thread_bundle.h"
@@ -138,14 +137,14 @@ class PasswordStoreWinTest : public testing::Test {
 
     base::FilePath path = temp_dir_.GetPath().AppendASCII("web_data_test");
     wdbs_ = new WebDatabaseService(
-        path, BrowserThread::GetTaskRunnerForThread(BrowserThread::UI),
+        path, base::ThreadTaskRunnerHandle::Get(),
         BrowserThread::GetTaskRunnerForThread(BrowserThread::DB));
     // Need to add at least one table so the database gets created.
     wdbs_->AddTable(std::unique_ptr<WebDatabaseTable>(new LoginsTable()));
     wdbs_->LoadDatabase();
-    wds_ = new PasswordWebDataService(
-        wdbs_, BrowserThread::GetTaskRunnerForThread(BrowserThread::UI),
-        WebDataServiceBase::ProfileErrorCallback());
+    wds_ =
+        new PasswordWebDataService(wdbs_, base::ThreadTaskRunnerHandle::Get(),
+                                   WebDataServiceBase::ProfileErrorCallback());
     wds_->Init();
   }
 
@@ -189,7 +188,6 @@ class PasswordStoreWinTest : public testing::Test {
 };
 
 ACTION(QuitUIMessageLoop) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
   base::MessageLoop::current()->QuitWhenIdle();
 }