Enable IO when starting the license server

chrome/browser/media/encrypted_media_browsertest.cc

 // Copyright 2013 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 <memory>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 #include "chrome/browser/media/media_browsertest.h"
 #include "chrome/browser/media/test_license_server.h"
 #include "chrome/browser/media/wv_test_license_server_config.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/test_launcher_utils.h"
@@ skipping 192 matching lines @@
 
   // Starts a license server if available for the |key_system| and adds a
   // 'licenseServerURL' query parameter to |query_params|.
   void StartLicenseServerIfNeeded(const std::string& key_system,
                                   base::StringPairs* query_params) {
     std::unique_ptr<TestLicenseServerConfig> config =
         GetServerConfig(key_system);
     if (!config)
       return;
     license_server_.reset(new TestLicenseServer(std::move(config)));
-    EXPECT_TRUE(license_server_->Start());
+    {
+      base::ThreadRestrictions::ScopedAllowIO allow_io;
+      EXPECT_TRUE(license_server_->Start());
+    }
     query_params->push_back(
         std::make_pair("licenseServerURL", license_server_->GetServerURL()));
   }
 
   bool IsPlayBackPossible(const std::string& key_system) {
 #if defined(WIDEVINE_CDM_AVAILABLE)
     if (IsWidevine(key_system) && !GetServerConfig(key_system))
       return false;
 #endif  // defined(WIDEVINE_CDM_AVAILABLE)
     return true;
@@ skipping 504 matching lines @@
 #endif  // BUILDFLAG(ENABLE_PEPPER_CDMS)
 
 #if BUILDFLAG(ENABLE_CDM_HOST_VERIFICATION)
 IN_PROC_BROWSER_TEST_F(ECKEncryptedMediaTest, VerifyCdmHostTest) {
   TestNonPlaybackCases(kExternalClearKeyVerifyCdmHostTestKeySystem,
                        kUnitTestSuccess);
 }
 #endif  // BUILDFLAG(ENABLE_CDM_HOST_VERIFICATION)
 
 }  // namespace chrome