patch from issue 2577273002 at patchset 20001 (http://crrev.com/2577273002#ps20001)

chrome/browser/icon_loader.cc

Index: chrome/browser/icon_loader.cc
diff --git a/chrome/browser/icon_loader.cc b/chrome/browser/icon_loader.cc
index 262bc54a12e8aea0c863edebbf6809fb332df9e4..976320e0a3d4b7bfc552bb2be8643e9e4a9a378e 100644
--- a/chrome/browser/icon_loader.cc
+++ b/chrome/browser/icon_loader.cc
@@ -12,10 +12,8 @@ using content::BrowserThread;
 
 IconLoader::IconLoader(const base::FilePath& file_path,
                        IconSize size,
-                       Delegate* delegate)
-    : file_path_(file_path),
-      icon_size_(size),
-      delegate_(delegate) {}
+                       IconLoadedCallback callback)
+    : file_path_(file_path), icon_size_(size), callback_(std::move(callback)) {}
 
 IconLoader::~IconLoader() {
 }
@@ -23,9 +21,10 @@ IconLoader::~IconLoader() {
 void IconLoader::Start() {
   target_task_runner_ = base::ThreadTaskRunnerHandle::Get();
 
-  BrowserThread::PostTaskAndReply(BrowserThread::FILE, FROM_HERE,
-      base::Bind(&IconLoader::ReadGroup, this),
-      base::Bind(&IconLoader::OnReadGroup, this));
+  BrowserThread::PostTaskAndReply(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&IconLoader::ReadGroup, base::Unretained(this)),
+      base::Bind(&IconLoader::OnReadGroup, base::Unretained(this)));
 }
 
 void IconLoader::ReadGroup() {
@@ -33,10 +32,7 @@ void IconLoader::ReadGroup() {
 }
 
 void IconLoader::OnReadGroup() {
-  BrowserThread::PostTask(ReadIconThreadID(), FROM_HERE,
-                          base::Bind(&IconLoader::ReadIcon, this));
-}
-
-void IconLoader::NotifyDelegate() {
-  delegate_->OnImageLoaded(this, std::move(image_), group_);
+  BrowserThread::PostTask(
+      ReadIconThreadID(), FROM_HERE,
+      base::Bind(&IconLoader::ReadIcon, base::Unretained(this)));
 }