Component updater on-demand logic with ResourceThrottle

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/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/component_updater/component_updater_service.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/extension_renderer_state.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"
 #include "chrome/browser/metrics/variations/variations_http_header_provider.h"
@@ skipping 162 matching lines @@
   } else if (url.SchemeIs("chrome-extension")) {
     ReportPrerenderSchemeCancelReason(
         PRERENDER_SCHEME_CANCEL_REASON_CHROME_EXTENSION);
   } else if (url.SchemeIs("about")) {
     ReportPrerenderSchemeCancelReason(PRERENDER_SCHEME_CANCEL_REASON_ABOUT);
   } else {
     ReportPrerenderSchemeCancelReason(PRERENDER_SCHEME_CANCEL_REASON_UNKNOWN);
   }
 }
 
+void AppendComponentUpdaterThrottles(
+    net::URLRequest* request,
+    content::ResourceContext* resource_context,
+    ResourceType::Type resource_type,
+    ScopedVector<content::ResourceThrottle>* throttles) {
+  const char* crx_id = NULL;
+  ComponentUpdateService* cus = g_browser_process->component_updater();
+  if (!cus)
+    return;
+  // Check for PNaCL nexe request.
+  if (resource_type == ResourceType::OBJECT) {
+    const net::HttpRequestHeaders& headers = request->extra_request_headers();
+    std::string accept_headers;
+    if (headers.GetHeader("Accept", &accept_headers)) {
+      if (accept_headers.find("application/x-pnacl") != std::string::npos)
+        crx_id = "hnimpnehoodheedghdeeijklkeaacbdc";
+    }
+  }
+
+  if (crx_id) {
+    // We got a component we need to install, so throttle the resource
+    // until the component is installed.
+    throttles->push_back(cus->GetOnDemandResourceThrottle(request, crx_id));
+  }
+}
+
 }  // end namespace
 
 ChromeResourceDispatcherHostDelegate::ChromeResourceDispatcherHostDelegate(
     prerender::PrerenderTracker* prerender_tracker)
     : download_request_limiter_(g_browser_process->download_request_limiter()),
       safe_browsing_(g_browser_process->safe_browsing_service()),
       user_script_listener_(new extensions::UserScriptListener()),
       prerender_tracker_(prerender_tracker) {
 }
 
@@ skipping 106 matching lines @@
   }
 
 #if defined(ENABLE_ONE_CLICK_SIGNIN)
   AppendChromeSyncGaiaHeader(request, resource_context);
 #endif
 
   AppendStandardResourceThrottles(request,
                                   resource_context,
                                   resource_type,
                                   throttles);
+  if (!is_prerendering) {
+    AppendComponentUpdaterThrottles(request,
+                                    resource_context,
+                                    resource_type,
+                                    throttles);
+  }
 
   if (io_data->resource_prefetch_predictor_observer()) {
     io_data->resource_prefetch_predictor_observer()->OnRequestStarted(
         request, resource_type, child_id, route_id);
   }
 }
 
 void ChromeResourceDispatcherHostDelegate::WillTransferRequestToNewProcess(
     int old_child_id,
     int old_route_id,
@@ skipping 331 matching lines @@
   if (!prerender::PrerenderManager::DoesURLHaveValidScheme(redirect_url) &&
       ResourceRequestInfo::ForRequest(request)->GetAssociatedRenderView(
           &child_id, &route_id) &&
       prerender_tracker_->IsPrerenderingOnIOThread(child_id, route_id) &&
       prerender_tracker_->TryCancel(
           child_id, route_id, prerender::FINAL_STATUS_UNSUPPORTED_SCHEME)) {
     ReportUnsupportedPrerenderScheme(redirect_url);
     request->Cancel();
   }
 }