Make `content` target build without unused data members on Linux.

content/renderer/renderer_main_platform_delegate_mac.mm

 // Copyright (c) 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/renderer/renderer_main_platform_delegate.h"
 
 #include <Carbon/Carbon.h>
 #import <Cocoa/Cocoa.h>
 #include <objc/runtime.h>
 #include <stdint.h>
@@ skipping 89 matching lines @@
             NULL)) {
       CFMachPortInvalidate(mach_port);
       return;
     }
   }
 }
 
 }  // namespace
 
 RendererMainPlatformDelegate::RendererMainPlatformDelegate(
-    const MainFunctionParams& parameters)
-        : parameters_(parameters) {
-}
+    const MainFunctionParams& parameters) {}
 
 RendererMainPlatformDelegate::~RendererMainPlatformDelegate() {
 }
 
 // TODO(mac-port): Any code needed to initialize a process for purposes of
 // running a renderer needs to also be reflected in chrome_main.cc for
 // --single-process support.
 void RendererMainPlatformDelegate::PlatformInitialize() {
   if (base::mac::IsOSYosemiteOrLater()) {
     // This is needed by the NSAnimations run for the scrollbars. If we switch
@@ skipping 20 matching lines @@
   // The sandbox is now engaged. Make sure that the renderer has not connected
   // itself to Cocoa.
   CHECK(NSApp == nil);
 
   DisconnectCFNotificationCenter();
 
   return sandbox_initialized;
 }
 
 }  // namespace content