Make URLDataSource::GetSource() const.

content/public/browser/url_data_source.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_
 #define CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 19 matching lines @@
 class CONTENT_EXPORT URLDataSource {
  public:
   // Adds a URL data source to |browser_context|.
   static void Add(BrowserContext* browser_context, URLDataSource* source);
 
   virtual ~URLDataSource() {}
 
   // The name of this source.
   // E.g., for favicons, this could be "favicon", which results in paths for
   // specific resources like "favicon/34" getting sent to this source.
-  virtual std::string GetSource() = 0;
+  virtual std::string GetSource() const = 0;
 
   // Used by StartDataRequest so that the child class can return the data when
   // it's available.
   typedef base::Callback<void(base::RefCountedMemory*)> GotDataCallback;
 
   // Called by URLDataSource to request data at |path|. The string parameter is
   // the path of the request. The child class should run |callback| when the
   // data is available or if the request could not be satisfied. This can be
   // called either in this callback or asynchronously with the response.
   virtual void StartDataRequest(const std::string& path,
@@ skipping 53 matching lines @@
   // Override in specific WebUI data sources to enable for additional schemes or
   // to implement fancier access control.  Typically used in concert with
   // ContentBrowserClient::GetAdditionalWebUISchemes() to permit additional
   // WebUI scheme support for an embedder.
   virtual bool ShouldServiceRequest(const net::URLRequest* request) const;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_