media: Convert mojo media defines to buildflags

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 23c5a3187f820242d91e0b8727c58a05a1152487..5d538fab5ffcaab335cb4dafb12b55bcda3710d8 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -98,6 +98,7 @@
 #include "media/base/media.h"
 #include "media/base/user_input_monitor.h"
 #include "media/midi/midi_service.h"
+#include "media/mojo/features.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/edk/embedder/scoped_ipc_support.h"
 #include "net/base/network_change_notifier.h"
@@ -190,7 +191,7 @@
 #include "content/browser/plugin_service_impl.h"
 #endif
 
-#if defined(ENABLE_MOJO_CDM) && BUILDFLAG(ENABLE_PEPPER_CDMS)
+#if BUILDFLAG(ENABLE_MOJO_CDM) && BUILDFLAG(ENABLE_PEPPER_CDMS)
 #include "content/browser/media/cdm_registry_impl.h"
 #endif
 
@@ -863,7 +864,7 @@ int BrowserMainLoop::PreCreateThreads() {
   }
 #endif
 
-#if defined(ENABLE_MOJO_CDM) && BUILDFLAG(ENABLE_PEPPER_CDMS)
+#if BUILDFLAG(ENABLE_MOJO_CDM) && BUILDFLAG(ENABLE_PEPPER_CDMS)
   // Prior to any processing happening on the IO thread, we create the
   // CDM service as it is predominantly used from the IO thread. This must
   // be called on the main thread since it involves file path checks.