Move enable_webrtc to a buildflag header.

chrome/test/base/testing_browser_process.cc

Index: chrome/test/base/testing_browser_process.cc
diff --git a/chrome/test/base/testing_browser_process.cc b/chrome/test/base/testing_browser_process.cc
index 72409a87fca65add4fcfaba9f60958d13a0bbd89..50d08b809e3cd298366f67fe4e85b56fa42c1826 100644
--- a/chrome/test/base/testing_browser_process.cc
+++ b/chrome/test/base/testing_browser_process.cc
@@ -25,6 +25,7 @@
 #include "components/subresource_filter/core/browser/ruleset_service.h"
 #include "content/public/browser/notification_service.h"
 #include "extensions/features/features.h"
+#include "media/media_features.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "printing/features/features.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -348,7 +349,7 @@ bool TestingBrowserProcess::created_local_state() const {
   return (local_state_ != nullptr);
 }
 
-#if defined(ENABLE_WEBRTC)
+#if BUILDFLAG(ENABLE_WEBRTC)
 WebRtcLogUploader* TestingBrowserProcess::webrtc_log_uploader() {
   return nullptr;
 }