Convert enable_plugins to a buildflag header.

chrome/browser/download/download_target_determiner_unittest.cc

Index: chrome/browser/download/download_target_determiner_unittest.cc
diff --git a/chrome/browser/download/download_target_determiner_unittest.cc b/chrome/browser/download/download_target_determiner_unittest.cc
index ca44f4c00888594245deb73de26ba3690070c565..e443b2d3e400766dc7ce82ec60887943d37c77c6 100644
--- a/chrome/browser/download/download_target_determiner_unittest.cc
+++ b/chrome/browser/download/download_target_determiner_unittest.cc
@@ -39,11 +39,12 @@
 #include "content/public/test/web_contents_tester.h"
 #include "extensions/features/features.h"
 #include "net/base/mime_util.h"
+#include "ppapi/features/features.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/origin.h"
 
-#if defined(ENABLE_PLUGINS)
+#if BUILDFLAG(ENABLE_PLUGINS)
 #include "content/public/browser/plugin_service.h"
 #include "content/public/browser/plugin_service_filter.h"
 #include "content/public/common/webplugininfo.h"
@@ -1915,7 +1916,7 @@ TEST_F(DownloadTargetDeterminerTest, MIMETypeDetermination) {
   }
 }
 
-#if defined(ENABLE_PLUGINS)
+#if BUILDFLAG(ENABLE_PLUGINS)
 
 void DummyGetPluginsCallback(
     const base::Closure& closure,
@@ -2163,6 +2164,6 @@ TEST_F(DownloadTargetDeterminerTestWithPlugin,
   EXPECT_FALSE(target_info->is_filetype_handled_safely);
 }
 
-#endif  // defined(ENABLE_PLUGINS)
+#endif  // BUILDFLAG(ENABLE_PLUGINS)
 
 }  // namespace