Convert enable_plugins to a buildflag header.

chrome/browser/renderer_host/chrome_render_message_filter.cc

Index: chrome/browser/renderer_host/chrome_render_message_filter.cc
diff --git a/chrome/browser/renderer_host/chrome_render_message_filter.cc b/chrome/browser/renderer_host/chrome_render_message_filter.cc
index 14d90e85b1ae2ea9389d449106c01297dc8895b7..257b6d8d41b6299625051cfb12d1c4e3dbb16429 100644
--- a/chrome/browser/renderer_host/chrome_render_message_filter.cc
+++ b/chrome/browser/renderer_host/chrome_render_message_filter.cc
@@ -30,6 +30,7 @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/service_worker_context.h"
 #include "extensions/features/features.h"
+#include "ppapi/features/features.h"
 
 #if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "extensions/browser/guest_view/web_view/web_view_permission_helper.h"
@@ -82,7 +83,7 @@ bool ChromeRenderMessageFilter::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_RequestFileSystemAccessAsync,
                         OnRequestFileSystemAccessAsync)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_AllowIndexedDB, OnAllowIndexedDB)
-#if defined(ENABLE_PLUGINS)
+#if BUILDFLAG(ENABLE_PLUGINS)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_IsCrashReportingEnabled,
                         OnIsCrashReportingEnabled)
 #endif
@@ -98,7 +99,7 @@ void ChromeRenderMessageFilter::OverrideThreadForMessage(
     const IPC::Message& message, BrowserThread::ID* thread) {
   switch (message.type()) {
     case NetworkHintsMsg_NavigationHint::ID:
-#if defined(ENABLE_PLUGINS)
+#if BUILDFLAG(ENABLE_PLUGINS)
     case ChromeViewHostMsg_IsCrashReportingEnabled::ID:
 #endif
     case ChromeViewHostMsg_UpdatedCacheStats::ID:
@@ -345,7 +346,7 @@ void ChromeRenderMessageFilter::OnAllowIndexedDB(int render_frame_id,
                  !*allowed));
 }
 
-#if defined(ENABLE_PLUGINS)
+#if BUILDFLAG(ENABLE_PLUGINS)
 void ChromeRenderMessageFilter::OnIsCrashReportingEnabled(bool* enabled) {
   *enabled = ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled();
 }