Cache JumpList icons to avoid unnecessary creation and deletion

chrome/browser/win/jumplist_updater.h

Index: chrome/browser/win/jumplist_updater.h
diff --git a/chrome/browser/win/jumplist_updater.h b/chrome/browser/win/jumplist_updater.h
index 4cbd3a1d1ca04c9e07173c2efc3ba9d88cb77e1a..d422a1c9271efb10b371b386b5f43400e644ec68 100644
--- a/chrome/browser/win/jumplist_updater.h
+++ b/chrome/browser/win/jumplist_updater.h
@@ -28,6 +28,7 @@ class ShellLinkItem : public base::RefCountedThreadSafe<ShellLinkItem> {
 
   const base::string16& title() const { return title_; }
   const base::string16& icon_path() const { return icon_path_; }
+  const std::string& url() const { return url_; }
   int icon_index() const { return icon_index_; }
   const gfx::ImageSkia& icon_image() const { return icon_image_; }
 
@@ -35,11 +36,11 @@ class ShellLinkItem : public base::RefCountedThreadSafe<ShellLinkItem> {
   base::CommandLine* GetCommandLine();
 
   void set_title(const base::string16& title) { title_ = title; }
-
   void set_icon(const base::string16& path, int index) {
     icon_path_ = path;
     icon_index_ = index;
   }
+  void set_url(const std::string& url) { url_ = url; }
 
   void set_icon_image(const gfx::ImageSkia& image) {
     icon_image_ = image;
@@ -58,6 +59,9 @@ class ShellLinkItem : public base::RefCountedThreadSafe<ShellLinkItem> {
   // The absolute path to an icon to be displayed in a JumpList.
   base::string16 icon_path_;
 
+  // The URL from which the favicon is retrieved.

[grt (UTC plus 2), 2017/05/18 09:00:00]

nit: is this the url of the favicon itself, or is it the url of the page to
which the favicon corresponds? if the latter, i propose:

The tab URL corresponding to this link's favicon.

[chengx, 2017/05/18 17:21:55]

Done. It's the latter one, i.e., the url of the page to which the favicon
corresponds.

+  std::string url_;
+
   // The icon index in the icon file. If an icon file consists of two or more
   // icons, set this value to identify the icon. If an icon file consists of
   // one icon, this value is 0.