Make some updates to extension iconography.

chrome/browser/extensions/api/management/chrome_management_api_delegate.cc

 // Copyright 2014 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/management/chrome_management_api_delegate.h"
 
 #include "base/callback_helpers.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 320 matching lines @@
     content::BrowserContext* context,
     const std::string& extension_id,
     extensions::LaunchType launch_type) const {
   extensions::SetLaunchType(context, extension_id, launch_type);
 }
 
 GURL ChromeManagementAPIDelegate::GetIconURL(
     const extensions::Extension* extension,
     int icon_size,
     ExtensionIconSet::MatchType match,
-    bool grayscale,
-    bool* exists) const {
+    bool grayscale) const {
   return extensions::ExtensionIconSource::GetIconURL(extension, icon_size,
-                                                     match, grayscale, exists);
+                                                     match, grayscale);
 }