Try to flush DOMStorage too when ending the browsing session.

chrome/browser/browser_process_impl.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 "chrome/browser/browser_process_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
+#include <iterator>
 #include <map>
 #include <utility>
 #include <vector>
 
 #include "base/atomic_ref_count.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/crash_logging.h"
 #include "base/debug/leak_annotations.h"
@@ skipping 371 matching lines @@
   //
   // This is important also because in various places, the
   // IOThread object being NULL is considered synonymous with the
   // IO thread having stopped.
   io_thread_.reset();
 }
 #endif  // !defined(OS_ANDROID)
 
 namespace {
 
+using TaskRunnerVector = std::vector<scoped_refptr<base::SequencedTaskRunner>>;
+
 // Used at the end of session to block the UI thread for completion of sentinel
 // tasks on the set of threads used to persist profile data and local state.
 // This is done to ensure that the data has been persisted to disk before
 // continuing.
 class RundownTaskCounter :
     public base::RefCountedThreadSafe<RundownTaskCounter> {
  public:
   RundownTaskCounter();
 
   // Posts a rundown task to |task_runner|, can be invoked an arbitrary number
   // of times before calling TimedWait.
   void Post(base::SequencedTaskRunner* task_runner);
 
+  // Posts a rundown task to each runner in |runners|, where the rundown task
+  // for runner[n+1] is posted during rundown task execution for runner[n].
+  void PostSerially(TaskRunnerVector runners);
+
   // Waits until the count is zero or |end_time| is reached.
   // This can only be called once per instance. Returns true if a count of zero
   // is reached or false if the |end_time| is reached. It is valid to pass an
   // |end_time| in the past.
   bool TimedWaitUntil(const base::TimeTicks& end_time);
 
  private:
   friend class base::RefCountedThreadSafe<RundownTaskCounter>;
   ~RundownTaskCounter() {}
 
   // Decrements the counter and releases the waitable event on transition to
   // zero.
   void Decrement();
 
+  void RundownSerially(TaskRunnerVector::const_iterator it,
+                       TaskRunnerVector runner);
+
   // The count starts at one to defer the possibility of one->zero transitions
   // until TimedWait is called.
   base::AtomicRefCount count_;
   base::WaitableEvent waitable_event_;
 
   DISALLOW_COPY_AND_ASSIGN(RundownTaskCounter);
 };
 
 RundownTaskCounter::RundownTaskCounter()
     : count_(1),
       waitable_event_(base::WaitableEvent::ResetPolicy::MANUAL,
                       base::WaitableEvent::InitialState::NOT_SIGNALED) {}
 
 void RundownTaskCounter::Post(base::SequencedTaskRunner* task_runner) {
   // As the count starts off at one, it should never get to zero unless
   // TimedWait has been called.
   DCHECK(!base::AtomicRefCountIsZero(&count_));
 
   base::AtomicRefCountInc(&count_);
 
   // The task must be non-nestable to guarantee that it runs after all tasks
   // currently scheduled on |task_runner| have completed.
   task_runner->PostNonNestableTask(FROM_HERE,
       base::Bind(&RundownTaskCounter::Decrement, this));
 }
 
+void RundownTaskCounter::PostSerially(TaskRunnerVector runners) {
+  if (runners.empty())
+    return;
+  base::AtomicRefCountInc(&count_);
+  TaskRunnerVector::const_iterator it = runners.begin();
+  (*it)->PostNonNestableTask(
+      FROM_HERE, base::Bind(&RundownTaskCounter::RundownSerially, this, it + 1,
+                            base::Passed(&runners)));
+}
+
 void RundownTaskCounter::Decrement() {
   if (!base::AtomicRefCountDec(&count_))
     waitable_event_.Signal();
 }
 
 bool RundownTaskCounter::TimedWaitUntil(const base::TimeTicks& end_time) {
   // Decrement the excess count from the constructor.
   Decrement();
 
   return waitable_event_.TimedWaitUntil(end_time);
 }
 
+void RundownTaskCounter::RundownSerially(TaskRunnerVector::const_iterator it,
+                                         TaskRunnerVector runners) {
+  if (it == runners.end()) {
+    Decrement();
+    return;
+  }
+  (*it)->PostNonNestableTask(
+      FROM_HERE, base::Bind(&RundownTaskCounter::RundownSerially, this, it + 1,
+                            base::Passed(&runners)));
+}
+
+void FlushStoragePartition(scoped_refptr<RundownTaskCounter> rundown_counter,
+                           content::StoragePartition* partition) {
+  rundown_counter->PostSerially(partition->Flush());
+}
+
 }  // namespace
 
 void BrowserProcessImpl::EndSession() {
   // Mark all the profiles as clean.
   ProfileManager* pm = profile_manager();
   std::vector<Profile*> profiles(pm->GetLoadedProfiles());
   scoped_refptr<RundownTaskCounter> rundown_counter(new RundownTaskCounter());
   const bool pref_service_enabled =
       base::FeatureList::IsEnabled(features::kPrefService);
   std::vector<scoped_refptr<base::SequencedTaskRunner>> profile_writer_runners;
-  for (size_t i = 0; i < profiles.size(); ++i) {
-    Profile* profile = profiles[i];
+  for (Profile* profile : profiles) {
     profile->SetExitType(Profile::EXIT_SESSION_ENDED);
     if (profile->GetPrefs()) {
       profile->GetPrefs()->CommitPendingWrite();
       if (pref_service_enabled) {
         rundown_counter->Post(content::BrowserThread::GetTaskRunnerForThread(
                                   content::BrowserThread::IO)
                                   .get());
         profile_writer_runners.push_back(profile->GetIOTaskRunner());
       } else {
         rundown_counter->Post(profile->GetIOTaskRunner().get());
       }
     }
+    content::BrowserContext::ForEachStoragePartition(
+        profile, base::Bind(&FlushStoragePartition, rundown_counter));

[hashimoto, 2017/04/04 09:23:24]

This shouldn't be put before Local State.
Local State is more important than this.

   }
 
   // Tell the metrics service it was cleanly shutdown.
   metrics::MetricsService* metrics = g_browser_process->metrics_service();
   if (metrics && local_state()) {
     metrics->RecordStartOfSessionEnd();
 #if !defined(OS_CHROMEOS)
     // MetricsService lazily writes to prefs, force it to write now.
     // On ChromeOS, chrome gets killed when hangs, so no need to
     // commit metrics::prefs::kStabilitySessionEndCompleted change immediately.
@@ skipping 935 matching lines @@
 }
 
 void BrowserProcessImpl::OnAutoupdateTimer() {
   if (CanAutorestartForUpdate()) {
     DLOG(WARNING) << "Detected update.  Restarting browser.";
     RestartBackgroundInstance();
   }
 }
 
 #endif  // (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)