Enable a minimal content/ build on iOS

content/public/app/content_main_delegate.cc

Index: content/public/app/content_main_delegate.cc
diff --git a/content/public/app/content_main_delegate.cc b/content/public/app/content_main_delegate.cc
index 51a6742e9ebdf60fd7ecab560363c5db919ebae9..02557b745fd3207c9867cefc189fbb4409aaf207 100644
--- a/content/public/app/content_main_delegate.cc
+++ b/content/public/app/content_main_delegate.cc
@@ -5,9 +5,12 @@
 #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 {
 
@@ -50,15 +53,27 @@ ContentBrowserClient* ContentMainDelegate::CreateContentBrowserClient() {
 }
 
 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