Refactor TaskManager's favicon retrieval approach

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

Index: chrome/browser/task_management/providers/web_contents/renderer_task.cc
diff --git a/chrome/browser/task_management/providers/web_contents/renderer_task.cc b/chrome/browser/task_management/providers/web_contents/renderer_task.cc
index 371a7cb7b4b95b00749a6dfbd09dc3b7f31bc231..ca30ac750dd15e99591707ebeb60063e23cd64a9 100644
--- a/chrome/browser/task_management/providers/web_contents/renderer_task.cc
+++ b/chrome/browser/task_management/providers/web_contents/renderer_task.cc
@@ -78,9 +78,17 @@ RendererTask::RendererTask(const base::string16& title,
   // 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() {
@@ -138,6 +146,14 @@ 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) {