"Redirecting URLs to Packaged Apps" implementation: revised

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc

Index: chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
diff --git a/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc b/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
index 266d8e1b9ed2def0d49ea851cea7b0bc2193f9df..686786a9c9a26d7f37df7ca0296ff3ff5d417b51 100644
--- a/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
+++ b/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
@@ -9,6 +9,7 @@
 #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"
@@ -262,6 +263,11 @@ void ChromeResourceDispatcherHostDelegate::RequestBeginning(
     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(