Add a mojo bridge for PersistentPrefStore.

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index be342085d4c81cde97e4375b29079b4685152651..8d3d31874381317eb4ceef46c32ca3412137f5b7 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -76,6 +76,7 @@
 #include "chrome/browser/update_client/chrome_update_query_params_delegate.h"
 #include "chrome/common/channel_info.h"
 #include "chrome/common/chrome_constants.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/crash_keys.h"
@@ -139,6 +140,7 @@
 #endif
 
 #if !defined(OS_ANDROID)
+#include "chrome/browser/features.h"
 #include "chrome/browser/gcm/gcm_product_util.h"
 #include "chrome/browser/lifetime/keep_alive_registry.h"
 #include "chrome/browser/ui/user_manager.h"
@@ -194,7 +196,8 @@ static const int kUpdateCheckIntervalHours = 6;
 // and Windows. We have a timeout here because we're unable to run the UI
 // messageloop and there's some deadlock risk. Our only option is to exit
 // anyway.
-static const int kEndSessionTimeoutSeconds = 10;
+static constexpr base::TimeDelta kEndSessionTimeout =
+    base::TimeDelta::FromSeconds(10);
 #endif
 
 using content::BrowserThread;
@@ -467,12 +470,22 @@ void BrowserProcessImpl::EndSession() {
   ProfileManager* pm = profile_manager();
   std::vector<Profile*> profiles(pm->GetLoadedProfiles());
   scoped_refptr<RundownTaskCounter> rundown_counter(new RundownTaskCounter());
+  const bool kEnablePrefService =
+      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];
     profile->SetExitType(Profile::EXIT_SESSION_ENDED);
     if (profile->GetPrefs()) {
       profile->GetPrefs()->CommitPendingWrite();
-      rundown_counter->Post(profile->GetIOTaskRunner().get());
+      if (kEnablePrefService) {
+        rundown_counter->Post(content::BrowserThread::GetTaskRunnerForThread(
+                                  content::BrowserThread::IO)
+                                  .get());
+        profile_writer_runners.push_back(profile->GetIOTaskRunner());
+      } else {
+        rundown_counter->Post(profile->GetIOTaskRunner().get());
+      }
     }
   }
 
@@ -513,8 +526,16 @@ void BrowserProcessImpl::EndSession() {
   // GPU process synchronously. Because the system may not be allowing
   // processes to launch, this can result in a hang. See
   // http://crbug.com/318527.
-  rundown_counter->TimedWait(
-      base::TimeDelta::FromSeconds(kEndSessionTimeoutSeconds));
+  base::Time start = base::Time::Now();
+  if (rundown_counter->TimedWait(kEndSessionTimeout) && kEnablePrefService) {
+    scoped_refptr<RundownTaskCounter> profile_write_rundown_counter(
+        new RundownTaskCounter());
+    for (auto& profile_writer_runner : profile_writer_runners) {
+      profile_write_rundown_counter->Post(profile_writer_runner.get());
+    }
+    profile_write_rundown_counter->TimedWait(kEndSessionTimeout -
+                                             (base::Time::Now() - start));
+  }
 #else
   NOTIMPLEMENTED();
 #endif
@@ -1345,6 +1366,19 @@ void BrowserProcessImpl::Unpin() {
 
   CHECK(base::MessageLoop::current()->is_running());
 
+  if (base::FeatureList::IsEnabled(features::kPrefService)) {
+    bool fast_shutdown_enabled =
+#if !defined(OS_ANDROID)
+        base::FeatureList::IsEnabled(features::kDesktopFastShutdown);
+#else
+        false;
+#endif
+    for (auto* profile : profile_manager()->GetLoadedProfiles()) {
+      profile->SetExitType(fast_shutdown_enabled ? Profile::EXIT_SESSION_ENDED
+                                                 : Profile::EXIT_NORMAL);
+    }
+  }
+
 #if defined(OS_MACOSX)
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(ChromeBrowserMainPartsMac::DidEndMainMessageLoop));