Remove ImageLoadingTracker class

chrome/browser/extensions/api/webview/webview_api.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/webview/webview_api.h"
 
 #include "chrome/common/extensions/api/webview.h"
 #include "content/public/browser/render_view_host.h"
+#include "ui/gfx/image/image_skia.h"
 
 using namespace extensions::api::webview;
 
 WebviewExecuteScriptFunction::WebviewExecuteScriptFunction() {
 }
 
 WebviewExecuteScriptFunction::~WebviewExecuteScriptFunction() {
 }
 
 bool WebviewExecuteScriptFunction::RunImpl() {
@@ skipping 60 matching lines @@
     const ListValue& result) {
   if (error.empty()) {
     SetResult(result.DeepCopy());
   } else {
     SetError(error);
   }
   SendResponse(error.empty());
   Release();  // Added in RunImpl().
 }