Don't request missing favicon on every page request.

chrome/browser/favicon/favicon_tab_helper.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/favicon/favicon_tab_helper.h"
 
 #include "chrome/browser/favicon/favicon_handler.h"
 #include "chrome/browser/favicon/favicon_service_factory.h"
 #include "chrome/browser/favicon/favicon_util.h"
 #include "chrome/browser/history/history_service.h"
@@ skipping 117 matching lines @@
   }
   service->SetFavicons(entry->GetURL(), favicon.url, history::FAVICON,
                        favicon.image);
 }
 
 NavigationEntry* FaviconTabHelper::GetActiveEntry() {
   return web_contents()->GetController().GetActiveEntry();
 }
 
 int FaviconTabHelper::StartDownload(const GURL& url, int image_size) {
+  FaviconService* favicon_service = FaviconServiceFactory::GetForProfile(
+      profile_->GetOriginalProfile(), Profile::IMPLICIT_ACCESS);
+  if (favicon_service && favicon_service->WasUnableToDownloadFavicon(url)) {
+    DVLOG(1) << "Skip Failed FavIcon: " << url;
+    return 0;
+  }
+
   return web_contents()->DownloadImage(
       url,
       true,
       image_size,
       base::Bind(&FaviconTabHelper::DidDownloadFavicon,base::Unretained(this)));
 }
 
 void FaviconTabHelper::NotifyFaviconUpdated(bool icon_url_changed) {
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_FAVICON_UPDATED,
       content::Source<WebContents>(web_contents()),
       content::Details<bool>(&icon_url_changed));
   web_contents()->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB);
 }
 
 void FaviconTabHelper::NavigateToPendingEntry(
     const GURL& url,
     NavigationController::ReloadType reload_type) {
   if (reload_type != NavigationController::NO_RELOAD &&
       !profile_->IsOffTheRecord()) {
     FaviconService* favicon_service = FaviconServiceFactory::GetForProfile(
         profile_, Profile::IMPLICIT_ACCESS);
-    if (favicon_service)
+    if (favicon_service) {
       favicon_service->SetFaviconOutOfDateForPage(url);
+      if (reload_type == NavigationController::RELOAD_IGNORING_CACHE)
+        favicon_service->ClearUnableToDownloadFavicons();
+    }
   }
 }
 
 void FaviconTabHelper::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   // Get the favicon, either from history or request it from the net.
   FetchFavicon(details.entry->GetURL());
 }
 
 void FaviconTabHelper::DidUpdateFaviconURL(
     int32 page_id,
     const std::vector<content::FaviconURL>& candidates) {
   favicon_handler_->OnUpdateFaviconURL(page_id, candidates);
   if (touch_icon_handler_.get())
     touch_icon_handler_->OnUpdateFaviconURL(page_id, candidates);
 }
 
 void FaviconTabHelper::DidDownloadFavicon(
     int id,
+    int http_status_code,
     const GURL& image_url,
     int requested_size,
     const std::vector<SkBitmap>& bitmaps) {
+
+  if (bitmaps.empty() && http_status_code == 404) {

[palmer, 2013/05/13 17:22:47]

Maybe not just 404, but any 400 error code? I don't know if that is best; just
an idea.

[mef, 2013/05/14 18:47:08]

Initial CL did the same as Firefox - marked Favicon as missing on any error, but
per discussion with sky@ scope was limited to HTTP error 404, thus requiring
propagation of HTTP status up here.

+    DVLOG(1) << "Failed to Download Favicon:" << image_url;
+    FaviconService* favicon_service = FaviconServiceFactory::GetForProfile(
+        profile_->GetOriginalProfile(), Profile::IMPLICIT_ACCESS);
+    if (favicon_service)
+      favicon_service->UnableToDownloadFavicon(image_url);
+  }
+
   favicon_handler_->OnDidDownloadFavicon(
       id, image_url, requested_size, bitmaps);
   if (touch_icon_handler_.get()) {
     touch_icon_handler_->OnDidDownloadFavicon(
         id, image_url, requested_size, bitmaps);
   }
 }