Implement lossy pref behavior for JsonPrefStore.

net/http/transport_security_persister.cc

Index: net/http/transport_security_persister.cc
diff --git a/net/http/transport_security_persister.cc b/net/http/transport_security_persister.cc
index 08aa07e1c9112ae1d8046dfb59f3303d4240aea9..bc2d6697e4bcfefde2cae36e48bb7dd1a7a8fef9 100644
--- a/net/http/transport_security_persister.cc
+++ b/net/http/transport_security_persister.cc
@@ -94,7 +94,9 @@ TransportSecurityPersister::TransportSecurityPersister(
     const scoped_refptr<base::SequencedTaskRunner>& background_runner,
     bool readonly)
     : transport_security_state_(state),
-      writer_(profile_path.AppendASCII("TransportSecurity"), background_runner),
+      writer_(new base::ImportantFileWriterImpl(
+          profile_path.AppendASCII("TransportSecurity"),
+          background_runner)),
       foreground_runner_(base::MessageLoop::current()->message_loop_proxy()),
       background_runner_(background_runner),
       readonly_(readonly),
@@ -103,7 +105,7 @@ TransportSecurityPersister::TransportSecurityPersister(
 
   base::PostTaskAndReplyWithResult(
       background_runner_.get(), FROM_HERE,
-      base::Bind(&LoadState, writer_.path()),
+      base::Bind(&LoadState, writer_->path()),
       base::Bind(&TransportSecurityPersister::CompleteLoad,
                  weak_ptr_factory_.GetWeakPtr()));
 }
@@ -111,8 +113,8 @@ TransportSecurityPersister::TransportSecurityPersister(
 TransportSecurityPersister::~TransportSecurityPersister() {
   DCHECK(foreground_runner_->RunsTasksOnCurrentThread());
 
-  if (writer_.HasPendingWrite())
-    writer_.DoScheduledWrite();
+  if (writer_->HasPendingWrite())
+    writer_->DoScheduledWrite();
 
   transport_security_state_->SetDelegate(NULL);
 }
@@ -123,7 +125,7 @@ void TransportSecurityPersister::StateIsDirty(
   DCHECK_EQ(transport_security_state_, state);
 
   if (!readonly_)
-    writer_.ScheduleWrite(this);
+    writer_->ScheduleWrite(this);
 }
 
 bool TransportSecurityPersister::SerializeData(std::string* output) {