Move ENABLE_PEPPER_CDMS to a buildflag header.

components/cdm/renderer/widevine_key_system_properties.h

Index: components/cdm/renderer/widevine_key_system_properties.h
diff --git a/components/cdm/renderer/widevine_key_system_properties.h b/components/cdm/renderer/widevine_key_system_properties.h
index cb15e48b660ce2850f169276bd156291688f13a0..6dbc2fee78ce6105598bf0bf6b0fc2d25627d57e 100644
--- a/components/cdm/renderer/widevine_key_system_properties.h
+++ b/components/cdm/renderer/widevine_key_system_properties.h
@@ -7,6 +7,7 @@
 
 #include "build/build_config.h"
 #include "media/base/key_system_properties.h"
+#include "third_party/widevine/cdm/cdm_features.h"
 
 namespace cdm {
 
@@ -56,7 +57,7 @@ class WidevineKeySystemProperties : public media::KeySystemProperties {
   media::EmeFeatureSupport GetPersistentStateSupport() const override;
   media::EmeFeatureSupport GetDistinctiveIdentifierSupport() const override;
 
-#if defined(ENABLE_PEPPER_CDMS)
+#if BUILDFLAG(ENABLE_PEPPER_CDMS)
   std::string GetPepperType() const override;
 #endif