Split ResourceContext into its own file, and make it compile on iOS

content/browser/resource_context.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/browser/resource_context_impl.h"
+
+#if !defined(OS_IOS)
+#include "content/browser/renderer_host/resource_dispatcher_host_impl.h"
+#endif
+
+namespace content {
+
+ResourceContext::ResourceContext() {
+#if !defined(OS_IOS)
+  if (ResourceDispatcherHostImpl::Get())
+    ResourceDispatcherHostImpl::Get()->AddResourceContext(this);
+#endif
+}
+
+ResourceContext::~ResourceContext() {
+#if !defined(OS_IOS)
+  ResourceDispatcherHostImpl* rdhi = ResourceDispatcherHostImpl::Get();
+  if (rdhi) {
+    rdhi->CancelRequestsForContext(this);
+    rdhi->RemoveResourceContext(this);
+  }
+#endif
+}
+
+}  // namespace content