Reload favicon from HTTP cache on Ctrl+Refresh

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/chrome_notification_types.h"
 #include "chrome/browser/favicon/chrome_favicon_client.h"
 #include "chrome/browser/favicon/chrome_favicon_client_factory.h"
 #include "chrome/browser/favicon/favicon_handler.h"
@@ skipping 135 matching lines @@
 }
 
 int FaviconTabHelper::StartDownload(const GURL& url, int max_image_size) {
   FaviconService* favicon_service = FaviconServiceFactory::GetForProfile(
       profile_->GetOriginalProfile(), ServiceAccessType::IMPLICIT_ACCESS);
   if (favicon_service && favicon_service->WasUnableToDownloadFavicon(url)) {
     DVLOG(1) << "Skip Failed FavIcon: " << url;
     return 0;
   }
 
+  blink::WebURLRequest::CachePolicy cache_policy =
+      (bypass_cache_page_url_ == GetActiveURL())
+          ? blink::WebURLRequest::ReloadBypassingCache
+          : blink::WebURLRequest::UseProtocolCachePolicy;
+  bypass_cache_page_url_ = GURL();

[pkotwicz, 2015/02/19 16:47:02]

I used a separate variable to track whether the favicon should be fetched
bypassing the cache. It unlikely but possible for the favicon not to be cached
in the history database but to be cached in the HTTP cache (e.g. open a new
profile, navigate to http://www.google.com/favicon.ico, then navigate to
www.google.com and press Ctrl+F5)

+
   return web_contents()->DownloadImage(
-      url,
-      true,
-      max_image_size,
-      base::Bind(&FaviconTabHelper::DidDownloadFavicon,base::Unretained(this)));
+      url, true, max_image_size, cache_policy,
+      base::Bind(&FaviconTabHelper::DidDownloadFavicon,
+                 base::Unretained(this)));
 }
 
 bool FaviconTabHelper::IsOffTheRecord() {
   DCHECK(web_contents());
   return web_contents()->GetBrowserContext()->IsOffTheRecord();
 }
 
 const gfx::Image FaviconTabHelper::GetActiveFaviconImage() {
   return GetFaviconStatus().image;
 }
@@ skipping 52 matching lines @@
 content::FaviconStatus& FaviconTabHelper::GetFaviconStatus() {
   DCHECK(web_contents()->GetController().GetActiveEntry());
   return web_contents()->GetController().GetActiveEntry()->GetFavicon();
 }
 
 void FaviconTabHelper::DidStartNavigationToPendingEntry(
     const GURL& url,
     NavigationController::ReloadType reload_type) {
   if (reload_type != NavigationController::NO_RELOAD &&
       !profile_->IsOffTheRecord()) {
+    bypass_cache_page_url_ = url;

[pkotwicz, 2015/02/19 16:47:02]

Not sure if I should do this only if |reload_type| is
NavigationController::RELOAD_IGNORING_CACHE

+
     FaviconService* favicon_service = FaviconServiceFactory::GetForProfile(
         profile_, ServiceAccessType::IMPLICIT_ACCESS);
     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) {
   favicon_urls_.clear();
+
+  // Wait till the user navigates to a new URL to start checking the cache
+  // again. The cache may be ignored for non-reload navigations (e.g.
+  // history.replace() in-page navigation). This is allowed to increase the
+  // likelihood that "reloading a page ignoring the cache" redownloads the
+  // favicon. In particular, a page may do an in-page navigation before
+  // FaviconHandler has the time to determine that the favicon needs to be
+  // redownloaded.

[pkotwicz, 2015/02/19 16:47:02]

www.youtube.com calls history.replace() right after being navigated to

+  GURL url = details.entry->GetURL();
+  if (url != bypass_cache_page_url_)
+    bypass_cache_page_url_ = GURL();
+
   // Get the favicon, either from history or request it from the net.
-  FetchFavicon(details.entry->GetURL());
+  FetchFavicon(url);
 }
 
 // Returns favicon_base::IconType the given icon_type corresponds to.
 // TODO(jif): Move function to /components/favicon_base/content/
 // crbug.com/374281.
 favicon_base::IconType ToChromeIconType(
     content::FaviconURL::IconType icon_type) {
   switch (icon_type) {
     case content::FaviconURL::FAVICON:
       return favicon_base::FAVICON;
@@ skipping 40 matching lines @@
       favicon_service->UnableToDownloadFavicon(image_url);
   }
 
   favicon_handler_->OnDidDownloadFavicon(
       id, image_url, bitmaps, original_bitmap_sizes);
   if (touch_icon_handler_.get()) {
     touch_icon_handler_->OnDidDownloadFavicon(
         id, image_url, bitmaps, original_bitmap_sizes);
   }
 }