Revert of Handle RenderProcessHostImpl::SetBackgrounded on Windows

chrome/browser/renderer_host/render_process_host_chrome_browsertest.cc

Index: chrome/browser/renderer_host/render_process_host_chrome_browsertest.cc
diff --git a/chrome/browser/renderer_host/render_process_host_chrome_browsertest.cc b/chrome/browser/renderer_host/render_process_host_chrome_browsertest.cc
index 3af07310d830162c3fec50daad6493244d19b40f..72add927696654b4711f540c351d2b306cb72318 100644
--- a/chrome/browser/renderer_host/render_process_host_chrome_browsertest.cc
+++ b/chrome/browser/renderer_host/render_process_host_chrome_browsertest.cc
@@ -291,7 +291,13 @@
 // We don't change process priorities on Mac or Posix because the user lacks the
 // permission to raise a process' priority even after lowering it.
 #if defined(OS_WIN) || defined(OS_LINUX)
-IN_PROC_BROWSER_TEST_F(ChromeRenderProcessHostTest, Backgrounding) {
+#if defined(OS_WIN)
+// Flaky test: crbug.com/394368
+#define MAYBE_Backgrounding DISABLED_Backgrounding
+#else
+#define MAYBE_Backgrounding Backgrounding
+#endif
+IN_PROC_BROWSER_TEST_F(ChromeRenderProcessHostTest, MAYBE_Backgrounding) {
   if (!base::Process::CanBackgroundProcesses()) {
     LOG(ERROR) << "Can't background processes";
     return;