Remove a chrome dependency by removing Prerender from ResourceDispatcherHost.

chrome/browser/renderer_host/chrome_resource_dispatcher_host_observer.h

+// 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.
+
+#ifndef CHROME_BROWSER_RENDERER_HOST_CHROME_RESOURCE_DISPATCHER_HOST_OBSERVER_H_
+#define CHROME_BROWSER_RENDERER_HOST_CHROME_RESOURCE_DISPATCHER_HOST_OBSERVER_H_
+#pragma once
+
+#include "content/browser/renderer_host/resource_dispatcher_host.h"
+
+namespace prerender {
+class PrerenderTracker;
+}
+
+// Implements ResourceDispatcherHost::Observer. Currently used by the Prerender
+// system to abort requests and add to the load flags when a request begins.
+class ChromeResourceDispatcherHostObserver
+    : public ResourceDispatcherHost::Observer {
+ public:
+  // This class does not take ownership of the tracker but merely holds a
+  // reference to it to avoid accessing g_browser_process. The PrerenderTracker
+  // will be destroyed after the observer.
+  explicit ChromeResourceDispatcherHostObserver(
+      prerender::PrerenderTracker* prerender_tracker);
+  virtual ~ChromeResourceDispatcherHostObserver();
+
+  // ResourceDispatcherHost::Observer implementation.
+  virtual bool ShouldBeginRequest(
+      int child_id, int route_id,
+      const ResourceHostMsg_Request& request_data,
+      const content::ResourceContext& resource_context,
+      const GURL& referrer) OVERRIDE;
+
+  virtual void MutateLoadFlags(int child_id, int route_id,
+                               int* load_flags) OVERRIDE;
+
+ private:
+  prerender::PrerenderTracker* prerender_tracker_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeResourceDispatcherHostObserver);
+};
+
+#endif  // CHROME_BROWSER_RENDERER_HOST_CHROME_RESOURCE_DISPATCHER_HOST_OBSERVER_H_