ChromeOS: fix crash in HashWallpaperFilesIdStr.

chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager.cc

 // Copyright 2014 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/chromeos/login/users/wallpaper/wallpaper_manager.h"
 
 #include <stdint.h>
 #include <numeric>
 #include <utility>
 #include <vector>
 
 #include "ash/common/ash_constants.h"
 #include "ash/common/ash_switches.h"
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/shell.h"
 #include "ash/sysui/public/interfaces/wallpaper.mojom.h"
 #include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/sha1.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 135 matching lines @@
                  ::tolower);
   std::vector<uint8_t> data = *salt;
   std::copy(files_id_unhashed.begin(), files_id_unhashed.end(),
             std::back_inserter(data));
   base::SHA1HashBytes(data.data(), data.size(), binmd);
   std::string result = base::HexEncode(binmd, sizeof(binmd));
   std::transform(result.begin(), result.end(), result.begin(), ::tolower);
   return wallpaper::WallpaperFilesId::FromString(result);
 }
 
+// Returns true if HashWallpaperFilesIdStr will not assert().
+bool CanGetFilesId() {
+  return SystemSaltGetter::Get()->GetRawSalt();
+}
+
+// Call |closure| when HashWallpaperFilesIdStr will not assert().
+void CallWhenCanGetFilesId(const base::Closure& closure) {
+  SystemSaltGetter::Get()->AddOnSystemSaltReady(closure);
+}
+
 void SetKnownUserWallpaperFilesId(
     const AccountId& account_id,
     const wallpaper::WallpaperFilesId& wallpaper_files_id) {
   user_manager::known_user::SetStringPref(account_id, kWallpaperFilesId,
                                           wallpaper_files_id.id());
 }
 
 ash::sysui::mojom::WallpaperLayout WallpaperLayoutToMojo(
     wallpaper::WallpaperLayout layout) {
   switch (layout) {
@@ skipping 691 matching lines @@
     }
   }
 
   if (loading_.empty())
     FOR_EACH_OBSERVER(Observer, observers_, OnPendingListEmptyForTesting());
 }
 
 void WallpaperManager::SetPolicyControlledWallpaper(
     const AccountId& account_id,
     std::unique_ptr<user_manager::UserImage> user_image) {
+  if (!CanGetFilesId()) {
+    CallWhenCanGetFilesId(
+        base::Bind(&WallpaperManager::SetPolicyControlledWallpaper,
+                   weak_factory_.GetWeakPtr(), account_id,
+                   base::Passed(std::move(user_image))));
+    return;
+  }
+
   const wallpaper::WallpaperFilesId wallpaper_files_id = GetFilesId(account_id);
 
   if (!wallpaper_files_id.is_valid())
     LOG(FATAL) << "Wallpaper flies id if invalid!";
 
   SetCustomWallpaper(account_id, wallpaper_files_id, "policy-controlled.jpeg",
                      wallpaper::WALLPAPER_LAYOUT_CENTER_CROPPED,
                      user_manager::User::POLICY, user_image->image(),
                      true /* update wallpaper */);
 }
@@ skipping 272 matching lines @@
                                               &stored_value)) {
     return wallpaper::WallpaperFilesId::FromString(stored_value);
   }
   const std::string& old_id = account_id.GetUserEmail();  // Migrated
   const wallpaper::WallpaperFilesId files_id = HashWallpaperFilesIdStr(old_id);
   SetKnownUserWallpaperFilesId(account_id, files_id);
   return files_id;
 }
 
 }  // namespace chromeos