Enable a minimal content/ build on iOS

content/public/app/content_main_delegate.cc

 // 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/public/app/content_main_delegate.h"
 
 #include "content/public/browser/content_browser_client.h"
+
+#if !defined(OS_IOS)
 #include "content/public/plugin/content_plugin_client.h"
 #include "content/public/renderer/content_renderer_client.h"
 #include "content/public/utility/content_utility_client.h"
+#endif
 
 namespace content {
 
 bool ContentMainDelegate::BasicStartupComplete(int* exit_code) {
   return false;
 }
 
 int ContentMainDelegate::RunProcess(
     const std::string& process_type,
     const content::MainFunctionParams& main_function_params) {
@@ skipping 22 matching lines @@
   return NULL;
 }
 
 #endif
 
 ContentBrowserClient* ContentMainDelegate::CreateContentBrowserClient() {
   return new ContentBrowserClient();
 }
 
 ContentPluginClient* ContentMainDelegate::CreateContentPluginClient() {
+#if defined(OS_IOS)
+  return NULL;
+#else
   return new ContentPluginClient();
+#endif
 }
 
 ContentRendererClient* ContentMainDelegate::CreateContentRendererClient() {
+#if defined(OS_IOS)
+  return NULL;
+#else
   return new ContentRendererClient();
+#endif
 }
 
 ContentUtilityClient* ContentMainDelegate::CreateContentUtilityClient() {
+#if defined(OS_IOS)
+  return NULL;
+#else
   return new ContentUtilityClient();
+#endif
 }
 
 }  // namespace content