Remove a chrome dependency by removing Prerender from ResourceDispatcherHost.

chrome/browser/renderer_host/resource_dispatcher_host_observer.cc

+// Copyright (c) 2011 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 "base/logging.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/prerender/prerender_manager.h"
+#include "chrome/browser/prerender/prerender_tracker.h"
+#include "chrome/browser/renderer_host/resource_dispatcher_host_observer.h"
+#include "content/browser/browser_thread.h"
+#include "content/browser/resource_context.h"
+#include "content/common/resource_messages.h"
+#include "net/base/load_flags.h"
+
+ResourceDispatcherHostObserver::ResourceDispatcherHostObserver() {
+}
+
+ResourceDispatcherHostObserver::~ResourceDispatcherHostObserver() {
+}
+
+bool ResourceDispatcherHostObserver::ShouldBeginRequest(
+    int child_id, int route_id,
+    const ResourceHostMsg_Request& request_data,
+    const content::ResourceContext& resource_context,
+    const GURL& referrer) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  bool is_prerendering =
+      g_browser_process->prerender_tracker()->IsPrerenderingOnIOThread(
+          child_id, route_id);
+
+  // Handle a PREFETCH resource type.
+  if (request_data.resource_type == ResourceType::PREFETCH) {
+    // All PREFETCH requests should be GETs, but be defensive about it.
+    if (request_data.method != "GET")
+      return false;
+
+    // If prefetch is disabled, kill the request.
+    if (!ResourceDispatcherHost::is_prefetch_enabled())
+      return false;
+
+    // If prerendering is enabled, trigger a prerender for the URL and abort the
+    // request to prevent double-gets.
+    if (prerender::PrerenderManager::IsPrerenderingPossible()) {
+      BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+          NewRunnableFunction(prerender::HandlePrefetchTag,
+              resource_context.prerender_manager(),
+              child_id,
+              route_id,
+              request_data.url,
+              referrer,
+              is_prerendering));
+      return false;
+    }
+  }
+
+  // Abort any prerenders that spawn requests that use invalid HTTP methods.
+  if (is_prerendering &&
+      !prerender::PrerenderManager::IsValidHttpMethod(request_data.method)) {
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                            NewRunnableFunction(
+                                prerender::DestroyPreloadForRenderView,
+                                resource_context.prerender_manager(),
+                                child_id,
+                                route_id,
+                                prerender::FINAL_STATUS_INVALID_HTTP_METHOD));
+    return false;
+  }
+
+  return true;
+}
+
+void ResourceDispatcherHostObserver::MutateLoadFlags(int child_id,
+                                                     int route_id,
+                                                     int* load_flags) {
+  DCHECK(load_flags);
+  if (g_browser_process->prerender_tracker()->IsPrerenderingOnIOThread(
+          child_id, route_id)) {
+    *load_flags |= net::LOAD_PRERENDER;
+  }
+}