"Redirecting URLs to Packaged Apps" implementation: revised

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.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 "chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.h"
 
 #include <string>
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
+#include "chrome/browser/apps/app_url_redirector.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/download_resource_throttle.h"
 #include "chrome/browser/extensions/api/streams_private/streams_private_api.h"
 #include "chrome/browser/extensions/extension_info_map.h"
 #include "chrome/browser/extensions/user_script_listener.h"
 #include "chrome/browser/external_protocol/external_protocol_handler.h"
 #include "chrome/browser/google/google_util.h"
@@ skipping 233 matching lines @@
 
   ChromeURLRequestUserData* user_data =
       ChromeURLRequestUserData::Create(request);
   bool is_prerendering = prerender_tracker_->IsPrerenderingOnIOThread(
       child_id, route_id);
   if (is_prerendering) {
     user_data->set_is_prerender(true);
     request->SetPriority(net::IDLE);
   }
 
+  // This will redirect some navigations to apps that have registered
+  // themselves to handle matching URLs patterns using 'url_handlers' in
+  // the manifest.
+  throttles->push_back(AppUrlRedirector::CreateThrottleFor(request));

[darin (slow to review), 2013/09/05 22:52:15]

You are installing this throttle for each and every URL request, whether for
top-level frames, subframes or subresources.  Since you are adding a delay to
route through the UI thread, this can add up to a lot of wasted cycles.

I think you should probably only register your throttle for MAIN_FRAME resource
loads, and presumably not for pre-rendering requests. You probably need to make
sure these are not pre-rendered in some other way, right?

I think you should just duplicate the check that is done below in the OS_ANDROID
case.

[sergeygs, 2013/09/05 23:46:57]

Done. I meant to do that, but somehow left it like this after debugging back and
forth. I've also #ifdefed this out of ANDROID and IOS now.

+
 #if defined(OS_ANDROID)
   if (!is_prerendering && resource_type == ResourceType::MAIN_FRAME) {
     throttles->push_back(
         InterceptNavigationDelegate::CreateThrottleFor(request));
   }
 #endif
 #if defined(OS_CHROMEOS)
   if (resource_type == ResourceType::MAIN_FRAME) {
     // We check offline first, then check safe browsing so that we still can
     // block unsafe site after we remove offline page.
@@ skipping 362 matching lines @@
   if (!prerender::PrerenderManager::DoesURLHaveValidScheme(redirect_url) &&
       ResourceRequestInfo::ForRequest(request)->GetAssociatedRenderView(
           &child_id, &route_id) &&
       prerender_tracker_->IsPrerenderingOnIOThread(child_id, route_id)) {
     ReportUnsupportedPrerenderScheme(redirect_url);
     prerender_tracker_->TryCancel(
         child_id, route_id, prerender::FINAL_STATUS_UNSUPPORTED_SCHEME);
     request->Cancel();
   }
 }