Enable VP9 in MP4 by default

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"
@@ skipping 250 matching lines @@
     title_watcher->AlsoWaitForTitle(base::ASCIIToUTF16(kEmeUpdateFailed));
     title_watcher->AlsoWaitForTitle(base::ASCIIToUTF16(kEmeErrorEvent));
     title_watcher->AlsoWaitForTitle(
         base::ASCIIToUTF16(kEmeMessageUnexpectedType));
     title_watcher->AlsoWaitForTitle(
         base::ASCIIToUTF16(kEmeRenewalMissingHeader));
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kIgnoreAutoplayRestrictionsForTests);
-    command_line->AppendSwitch(switches::kEnableVp9InMp4);
   }
 
 #if BUILDFLAG(ENABLE_PEPPER_CDMS)
   void SetUpDefaultCommandLine(base::CommandLine* command_line) override {
     base::CommandLine default_command_line(base::CommandLine::NO_PROGRAM);
     InProcessBrowserTest::SetUpDefaultCommandLine(&default_command_line);
     test_launcher_utils::RemoveCommandLineSwitch(
         default_command_line, switches::kDisableComponentUpdate, command_line);
   }
 #endif  // BUILDFLAG(ENABLE_PEPPER_CDMS)
@@ skipping 457 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