Make some updates to extension iconography.

extensions/browser/api/management/management_api_delegate.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_API_MANAGEMENT_MANAGEMENT_API_DELEGATER_H_
 #define EXTENSIONS_BROWSER_API_MANAGEMENT_MANAGEMENT_API_DELEGATER_H_
 
 #include "base/callback.h"
 #include "extensions/browser/uninstall_reason.h"
 #include "extensions/common/constants.h"
@@ skipping 115 matching lines @@
   GenerateAppForLinkFunctionDelegate(
       ManagementGenerateAppForLinkFunction* function,
       content::BrowserContext* context,
       const std::string& title,
       const GURL& launch_url) const = 0;
 
   // Forwards the call to ExtensionIconSource::GetIconURL in chrome.
   virtual GURL GetIconURL(const Extension* extension,
                           int icon_size,
                           ExtensionIconSet::MatchType match,
-                          bool grayscale,
-                          bool* exists) const = 0;
+                          bool grayscale) const = 0;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_MANAGEMENT_MANAGEMENT_API_DELEGATER_H_