move favicon download code from chrome/ into content/

chrome/browser/ui/metro_pin_tab_helper_win.cc

Index: chrome/browser/ui/metro_pin_tab_helper_win.cc
diff --git a/chrome/browser/ui/metro_pin_tab_helper_win.cc b/chrome/browser/ui/metro_pin_tab_helper_win.cc
index 6491efa71cfdd04e38b9a93b3559196e82b0f558..a4d84110807ae091c55e9ed55e70f34857f74439 100644
--- a/chrome/browser/ui/metro_pin_tab_helper_win.cc
+++ b/chrome/browser/ui/metro_pin_tab_helper_win.cc
@@ -17,12 +17,10 @@
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "base/win/metro.h"
-#include "chrome/browser/favicon/favicon_download_helper.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
 #include "chrome/browser/favicon/favicon_util.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/common/chrome_paths.h"
-#include "chrome/common/icon_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
 #include "crypto/sha2.h"
@@ -350,9 +348,8 @@ void MetroPinTabHelper::FaviconChooser::AddPendingRequest(int request_id) {
 }
 
 MetroPinTabHelper::MetroPinTabHelper(content::WebContents* web_contents)
-    : content::WebContentsObserver(web_contents),
-      ALLOW_THIS_IN_INITIALIZER_LIST(
-          favicon_download_helper_(web_contents, this)) {
+    : content::WebContentsObserver(web_contents) {
+  web_contents->RegisterFaviconDelegate(this);
 }
 
 MetroPinTabHelper::~MetroPinTabHelper() {}
@@ -406,7 +403,7 @@ void MetroPinTabHelper::TogglePinnedToStartScreen() {
        iter != favicon_url_candidates_.end();
        ++iter) {
     favicon_chooser_->AddPendingRequest(
-        favicon_download_helper_.DownloadFavicon(iter->icon_url, image_size));
+        web_contents()->DownloadFavicon(iter->icon_url, image_size));
   }
 
 }
@@ -422,13 +419,13 @@ void MetroPinTabHelper::DidNavigateMainFrame(
   favicon_url_candidates_.clear();
 }
 
-void MetroPinTabHelper::OnUpdateFaviconURL(
+void MetroPinTabHelper::UpdateFaviconURL(
     int32 page_id,
     const std::vector<FaviconURL>& candidates) {
   favicon_url_candidates_ = candidates;
 }
 
-void MetroPinTabHelper::OnDidDownloadFavicon(
+void MetroPinTabHelper::DidDownloadFavicon(
     int id,
     const GURL& image_url,
     bool errored,