Refactor TaskManager's favicon retrieval approach

chrome/browser/task_management/providers/web_contents/renderer_task.cc

 // Copyright 2015 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/task_management/providers/web_contents/renderer_task.h"
 
 #include "base/i18n/rtl.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 60 matching lines @@
       renderer_resources_sampler_(
           CreateRendererResourcesSampler(render_process_host_)),
       render_process_id_(render_process_host_->GetID()),
       v8_memory_allocated_(0),
       v8_memory_used_(0),
       webcache_stats_(),
       profile_name_(GetRendererProfileName(render_process_host_)) {
   // All renderer tasks are capable of reporting network usage, so the default
   // invalid value of -1 doesn't apply here.
   OnNetworkBytesRead(0);
+
+  // Tag the web_contents with a |ContentFaviconDriver| (if needed) so that
+  // we can use it to observe favicons changes.
+  favicon::CreateContentFaviconDriverForWebContents(web_contents);
+  favicon::ContentFaviconDriver::FromWebContents(web_contents)->AddObserver(
+      this);
 }
 
 RendererTask::~RendererTask() {
+  favicon::ContentFaviconDriver::FromWebContents(web_contents())->
+      RemoveObserver(this);
 }
 
 void RendererTask::Activate() {
   if (!web_contents_->GetDelegate())
     return;
 
   web_contents_->GetDelegate()->ActivateContents(web_contents_);
 }
 
 void RendererTask::Refresh(const base::TimeDelta& update_interval,
@@ skipping 37 matching lines @@
 }
 
 bool RendererTask::ReportsWebCacheStats() const {
   return true;
 }
 
 blink::WebCache::ResourceTypeStats RendererTask::GetWebCacheStats() const {
   return webcache_stats_;
 }
 
+void RendererTask::OnFaviconAvailable(const gfx::Image& image) {
+}
+
+void RendererTask::OnFaviconUpdated(favicon::FaviconDriver* favicon_driver,
+                                    bool icon_url_changed) {
+  UpdateFavicon();
+}
+
 // static
 base::string16 RendererTask::GetTitleFromWebContents(
     content::WebContents* web_contents) {
   DCHECK(web_contents);
   base::string16 title = web_contents->GetTitle();
   if (title.empty()) {
     GURL url = web_contents->GetURL();
     title = base::UTF8ToUTF16(url.spec());
     // Force URL to be LTR.
     title = base::i18n::GetDisplayStringInLTRDirectionality(title);
@@ skipping 51 matching lines @@
     if (is_incognito)
       message_id = IDS_TASK_MANAGER_EXTENSION_INCOGNITO_PREFIX;
     else
       message_id = IDS_TASK_MANAGER_EXTENSION_PREFIX;
   }
 
   return l10n_util::GetStringFUTF16(message_id, title);
 }
 
 }  // namespace task_management