Declarative resource hints go through mojo IPC to //content

content/browser/loader/resource_hints_handler_impl.cc

+// Copyright 2016 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/loader/resource_hints_handler_impl.h"
+
+#include "base/memory/ptr_util.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/resource_context.h"
+#include "content/public/browser/resource_hints.h"
+
+namespace content {
+
+// static
+void ResourceHintsHandlerImpl::RegisterConnection(
+    RenderProcessHost* render_process_host,
+    blink::mojom::ResourceHintsHandlerRequest request) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&ResourceHintsHandlerImpl::RegisterConnectionOnIOThread,
+                 render_process_host->GetBrowserContext()->GetResourceContext(),
+                 base::Passed(&request)));
+}
+
+// static
+void ResourceHintsHandlerImpl::RegisterConnectionOnIOThread(
+    ResourceContext* resource_context,
+    blink::mojom::ResourceHintsHandlerRequest request) {
+  // Will be deleted when the connection goes away.
+  new ResourceHintsHandlerImpl(std::move(request), resource_context);
+}
+
+ResourceHintsHandlerImpl::ResourceHintsHandlerImpl(
+    blink::mojom::ResourceHintsHandlerRequest request,
+    ResourceContext* resource_context)
+    : resource_context_(resource_context), binding_(this, std::move(request)) {}
+
+ResourceHintsHandlerImpl::~ResourceHintsHandlerImpl() {}
+
+void ResourceHintsHandlerImpl::Preresolve(const GURL& url) {
+  PreresolveUrl(resource_context_, url, net::CompletionCallback());
+}
+
+void ResourceHintsHandlerImpl::Preconnect(const GURL& url,
+                                          bool credentials_flag,
+                                          uint8_t num_connections) {
+  // TODO(csharrison): Remove HttpRequestInfo::RequestMotivation and add a
+  // better enum at the //content layer.
+  PreconnectUrl(resource_context_, url, GURL(), num_connections,
+                credentials_flag, net::HttpRequestInfo::EARLY_LOAD_MOTIVATED);
+}
+
+}  // namespace content