Add PrerenderResourceHandler and hook it into the ResourceDispatcherHost....

chrome/browser/renderer_host/resource_dispatcher_host.cc

 // Copyright (c) 2010 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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include "chrome/browser/renderer_host/resource_dispatcher_host.h"
 
 #include <set>
 #include <vector>
@@ skipping 13 matching lines @@
 #include "chrome/browser/download/download_file_manager.h"
 #include "chrome/browser/download/download_manager.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/save_file_manager.h"
 #include "chrome/browser/extensions/user_script_listener.h"
 #include "chrome/browser/external_protocol_handler.h"
 #include "chrome/browser/in_process_webkit/webkit_thread.h"
 #include "chrome/browser/net/chrome_url_request_context.h"
 #include "chrome/browser/net/url_request_tracking.h"
 #include "chrome/browser/plugin_service.h"
+#include "chrome/browser/prerender/prerender_resource_handler.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_host/async_resource_handler.h"
 #include "chrome/browser/renderer_host/buffered_resource_handler.h"
 #include "chrome/browser/renderer_host/cross_site_resource_handler.h"
 #include "chrome/browser/renderer_host/download_resource_handler.h"
 #include "chrome/browser/renderer_host/global_request_id.h"
 #include "chrome/browser/renderer_host/redirect_to_file_resource_handler.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/renderer_host/render_view_host_delegate.h"
 #include "chrome/browser/renderer_host/render_view_host_notification_task.h"
@@ skipping 392 matching lines @@
   request->set_context(context);
   request->set_priority(DetermineRequestPriority(request_data.resource_type));
 
   // Set upload data.
   uint64 upload_size = 0;
   if (request_data.upload_data) {
     request->set_upload(request_data.upload_data);
     upload_size = request_data.upload_data->GetContentLength();
   }
 
+  // Install a PrerenderResourceHandler if the requested URL could
+  // be prerendered. This should be in front of the [a]syncResourceHandler,
+  // but after the BufferedResourceHandler since it depends on the MIME
+  // sniffing capabilities in the BufferedResourceHandler.
+  if (context && context->prerender_manager() &&
+      PrerenderResourceHandler::CouldPrerender(request)) {
+    handler = new PrerenderResourceHandler(handler,
+                                           context->prerender_manager());

[gavinp, 2010/12/17 16:15:33]

An idea, not sure if it's the right thing: how about PreRenderResourceHandler
has a private constructor, and instead there's a static method taking handler
and returning an handler, which hides CouldPrerender's call?  Two wins: this
call site is more succinct, and the unit test can check that CouldPrerender is
good?

[cbentzel, 2010/12/17 16:23:21]

I'm not sure I understand what you are asking for - or more importantly, the
value of it.

It seems like this would simply to change to

if (context && context->prerender_manager()) {
  handler = PrerenderResourceHandler::MaybeCreate(handler, request,
context->prerender_manager());
}

Where MaybeCreate would also need to return the passed in handler if
CouldPrerender is false. It seems like that makes the behavior less explicit at
the call site, and it doesn't make it that much more succinct.

I could add a unit test explicitly for CouldPrerender if desired.

+  }
+
   // Install a CrossSiteResourceHandler if this request is coming from a
   // RenderViewHost with a pending cross-site request.  We only check this for
   // MAIN_FRAME requests. Unblock requests only come from a blocked page, do
   // not count as cross-site, otherwise it gets blocked indefinitely.
   if (request_data.resource_type == ResourceType::MAIN_FRAME &&
       process_type == ChildProcessInfo::RENDER_PROCESS &&
       CrossSiteRequestManager::GetInstance()->
           HasPendingCrossSiteRequest(child_id, route_id)) {
     // Wrap the event handler to be sure the current page's onunload handler
     // has a chance to run before we render the new page.
@@ skipping 1448 matching lines @@
   return is_prefetch_enabled_;
 }
 
 // static
 void ResourceDispatcherHost::set_is_prefetch_enabled(bool value) {
   is_prefetch_enabled_ = value;
 }
 
 // static
 bool ResourceDispatcherHost::is_prefetch_enabled_ = false;