ChromeOS: fix crash in HashWallpaperFilesIdStr.

chromeos/cryptohome/system_salt_getter.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 "chromeos/cryptohome/system_salt_getter.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 24 matching lines @@
         FROM_HERE, base::Bind(callback, system_salt_));
     return;
   }
 
   DBusThreadManager::Get()->GetCryptohomeClient()->WaitForServiceToBeAvailable(
       base::Bind(&SystemSaltGetter::DidWaitForServiceToBeAvailable,
                  weak_ptr_factory_.GetWeakPtr(),
                  callback));
 }
 
+void SystemSaltGetter::AddOnSystemSaltReady(const base::Closure& closure) {
+  if (!raw_salt_.empty()) {
+    closure.Run();
+    return;
+  }
+
+  on_system_salt_ready_.push_back(closure);
+}
+
 const SystemSaltGetter::RawSalt* SystemSaltGetter::GetRawSalt() const {
   return raw_salt_.empty() ? nullptr : &raw_salt_;
 }
 
 void SystemSaltGetter::SetRawSaltForTesting(
     const SystemSaltGetter::RawSalt& raw_salt) {
   raw_salt_ = raw_salt;
 }
 
 void SystemSaltGetter::DidWaitForServiceToBeAvailable(
@@ skipping 12 matching lines @@
 
 void SystemSaltGetter::DidGetSystemSalt(
     const GetSystemSaltCallback& callback,
     DBusMethodCallStatus call_status,
     const std::vector<uint8_t>& system_salt) {
   if (call_status == DBUS_METHOD_CALL_SUCCESS &&
       !system_salt.empty() &&
       system_salt.size() % 2 == 0U) {
       raw_salt_ = system_salt;
     system_salt_ = ConvertRawSaltToHexString(system_salt);
+
+    std::vector<base::Closure> callbacks;
+    callbacks.swap(on_system_salt_ready_);
+    for (const base::Closure& callback : callbacks) {
+      callback.Run();
+    }
   } else {
     LOG(WARNING) << "System salt not available";
   }
 
   callback.Run(system_salt_);
 }
 
 // static
 void SystemSaltGetter::Initialize() {
   CHECK(!g_system_salt_getter);
@@ skipping 20 matching lines @@
 }
 
 // static
 std::string SystemSaltGetter::ConvertRawSaltToHexString(
     const std::vector<uint8_t>& salt) {
   return base::ToLowerASCII(
       base::HexEncode(reinterpret_cast<const void*>(salt.data()), salt.size()));
 }
 
 }  // namespace chromeos