Stop warnings resulting from unimplemented SetProcessBackgrounded().

content/browser/child_process_launcher.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/child_process_launcher.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/i18n/icu_util.h"
@@ skipping 295 matching lines @@
   } else
 #endif  // !OS_MACOSX
   base::EnsureProcessTerminated(process.Pass());
 #endif  // OS_POSIX
 #endif  // defined(OS_ANDROID)
 }
 
 void SetProcessBackgroundedOnLauncherThread(base::Process process,
                                             bool background) {
   DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
-  process.SetProcessBackgrounded(background);
+  if (process.CanBackgroundProcesses()) {
+    process.SetProcessBackgrounded(background);
+  }
 #if defined(OS_ANDROID)
   SetChildProcessInForeground(process.Handle(), !background);
 #endif
 }
 
 }  // anonymous namespace
 
 ChildProcessLauncher::ChildProcessLauncher(
     SandboxedProcessLauncherDelegate* delegate,
     base::CommandLine* cmd_line,
@@ skipping 214 matching lines @@
 }
 
 ChildProcessLauncher::Client* ChildProcessLauncher::ReplaceClientForTest(
     Client* client) {
   Client* ret = client_;
   client_ = client;
   return ret;
 }
 
 }  // namespace content