Move ENABLE_PEPPER_CDMS to a buildflag header.

chrome/common/render_messages.h

Index: chrome/common/render_messages.h
diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index fe396fc3a773dcc724e47798e0e6e0e2acc4160d..d3367fbb9fcbd3ee825737ff7059af357263c6f0 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -26,6 +26,7 @@
 #include "third_party/WebKit/public/platform/modules/app_banner/WebAppBannerPromptReply.h"
 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
 #include "third_party/WebKit/public/web/WebWindowFeatures.h"
+#include "third_party/widevine/cdm/cdm_features.h"
 #include "ui/base/window_open_disposition.h"
 #include "url/gurl.h"
 #include "url/ipc/url_param_traits.h"
@@ -428,7 +429,7 @@ IPC_SYNC_MESSAGE_CONTROL4_1(ChromeViewHostMsg_GetPluginInfo,
                             std::string /* mime_type */,
                             ChromeViewHostMsg_GetPluginInfo_Output /* output */)
 
-#if defined(ENABLE_PEPPER_CDMS)
+#if BUILDFLAG(ENABLE_PEPPER_CDMS)
 // Returns whether any internal plugin supporting |mime_type| is registered and
 // enabled. Does not determine whether the plugin can actually be instantiated
 // (e.g. whether it has all its dependencies).