Move enable extensions define to a build flag.

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 d9bd7a417f1a978b14959cd8412695f19643cac8..56bffc8912f3d611fd1915b42317f41c40097cc8 100644
--- a/chrome/renderer/pepper/pepper_uma_host.cc
+++ b/chrome/renderer/pepper/pepper_uma_host.cc
@@ -18,6 +18,7 @@
 #include "content/public/renderer/pepper_plugin_instance.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/renderer_ppapi_host.h"
+#include "extensions/features/features.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/features/features.h"
 #include "ppapi/host/dispatch_host_message.h"
@@ -27,10 +28,10 @@
 
 #include "widevine_cdm_version.h"  // In SHARED_INTERMEDIATE_DIR.
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
-#endif  // defined(ENABLE_EXTENSIONS)
+#endif  // BUILDFLAG(ENABLE_EXTENSIONS)
 
 namespace {
 
@@ -106,7 +107,7 @@ int32_t PepperUMAHost::OnResourceMessageReceived(
 }
 
 bool PepperUMAHost::IsPluginWhitelisted() {
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   return ChromeContentRendererClient::IsExtensionOrSharedModuleWhitelisted(
       document_url_, allowed_origins_);
 #else