Move ENABLE_PEPPER_CDMS to a buildflag header.

chrome/renderer/pepper/pepper_uma_host.cc

Index: chrome/renderer/pepper/pepper_uma_host.cc
diff --git a/chrome/renderer/pepper/pepper_uma_host.cc b/chrome/renderer/pepper/pepper_uma_host.cc
index 417483843899d8ab22b9410f6d384025301814a6..d9bd7a417f1a978b14959cd8412695f19643cac8 100644
--- a/chrome/renderer/pepper/pepper_uma_host.cc
+++ b/chrome/renderer/pepper/pepper_uma_host.cc
@@ -19,6 +19,7 @@
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/renderer_ppapi_host.h"
 #include "ppapi/c/pp_errors.h"
+#include "ppapi/features/features.h"
 #include "ppapi/host/dispatch_host_message.h"
 #include "ppapi/host/host_message_context.h"
 #include "ppapi/host/ppapi_host.h"
@@ -51,7 +52,7 @@ const char* const kWhitelistedHistogramPrefixes[] = {
 };
 
 const char* const kWhitelistedPluginBaseNames[] = {
-#if defined(WIDEVINE_CDM_AVAILABLE) && defined(ENABLE_PEPPER_CDMS)
+#if defined(WIDEVINE_CDM_AVAILABLE) && BUILDFLAG(ENABLE_PEPPER_CDMS)
     kWidevineCdmAdapterFileName,  // see http://crbug.com/368743
                                   // and http://crbug.com/410630
 #endif