Extract Favicon Download logic from FaviconTabHelper

chrome/browser/favicon/favicon_tab_helper.cc

Index: chrome/browser/favicon/favicon_tab_helper.cc
diff --git a/chrome/browser/favicon/favicon_tab_helper.cc b/chrome/browser/favicon/favicon_tab_helper.cc
index 6525b0664ab790bab6e94c762c9dfe502ccdd61c..e36cbbe3056b3c4edf3a4f9b57a37a6a8cc5ea58 100644
--- a/chrome/browser/favicon/favicon_tab_helper.cc
+++ b/chrome/browser/favicon/favicon_tab_helper.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/favicon/favicon_tab_helper.h"
 
+#include "chrome/browser/favicon/favicon_download_helper.h"
 #include "chrome/browser/favicon/favicon_handler.h"
 #include "chrome/browser/favicon/favicon_service_factory.h"
 #include "chrome/browser/favicon/favicon_util.h"
@@ -38,6 +39,7 @@ DEFINE_WEB_CONTENTS_USER_DATA_KEY(FaviconTabHelper)
 FaviconTabHelper::FaviconTabHelper(WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       profile_(Profile::FromBrowserContext(web_contents->GetBrowserContext())) {
+  favicon_download_helper_.reset(new FaviconDownloadHelper(web_contents, this));
   favicon_handler_.reset(new FaviconHandler(profile_, this,
                                             FaviconHandler::FAVICON));
   if (chrome::kEnableTouchIcon)
@@ -145,9 +147,7 @@ NavigationEntry* FaviconTabHelper::GetActiveEntry() {
 }
 
 int FaviconTabHelper::StartDownload(const GURL& url, int image_size) {
-  content::RenderViewHost* host = web_contents()->GetRenderViewHost();
-  int id = FaviconUtil::DownloadFavicon(host, url, image_size);
-  return id;
+  return favicon_download_helper_->DownloadFavicon(url, image_size);
 }
 
 void FaviconTabHelper::NotifyFaviconUpdated() {
@@ -177,16 +177,6 @@ void FaviconTabHelper::DidNavigateMainFrame(
   FetchFavicon(details.entry->GetURL());
 }
 
-bool FaviconTabHelper::OnMessageReceived(const IPC::Message& message) {
-  bool message_handled = false;   // Allow other handlers to receive these.
-  IPC_BEGIN_MESSAGE_MAP(FaviconTabHelper, message)
-    IPC_MESSAGE_HANDLER(IconHostMsg_DidDownloadFavicon, OnDidDownloadFavicon)
-    IPC_MESSAGE_HANDLER(IconHostMsg_UpdateFaviconURL, OnUpdateFaviconURL)
-    IPC_MESSAGE_UNHANDLED(message_handled = false)
-  IPC_END_MESSAGE_MAP()
-  return message_handled;
-}
-
 void FaviconTabHelper::OnDidDownloadFavicon(
     int id,
     const GURL& image_url,