WebUI: only crash Chrome for invalid chrome:// URLs in debug

content/browser/webui/shared_resources_data_source.cc

 // Copyright (c) 2012 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 "content/browser/webui/shared_resources_data_source.h"
 
 #include <stddef.h>
 
 #include "base/containers/hash_tables.h"
 #include "base/files/file_path.h"
@@ skipping 94 matching lines @@
   callback.Run(bytes.get());
 }
 
 std::string SharedResourcesDataSource::GetMimeType(
     const std::string& path) const {
   if (path.empty())
     return "text/html";
 
 #if defined(OS_WIN)
   base::FilePath file(base::UTF8ToWide(path));
-  std::string extension = base::WideToUTF8(file.FinalExtension()).substr(1);
+  std::string extension = base::WideToUTF8(file.FinalExtension());
 #else
   base::FilePath file(path);
-  std::string extension = file.FinalExtension().substr(1);
+  std::string extension = file.FinalExtension();
 #endif
 
+  if (!extension.empty())
+    extension.erase(0, 1);
+
   if (extension == "html")
     return "text/html";
 
   if (extension == "css")
     return "text/css";
 
   if (extension == "js")
     return "application/javascript";
 
   if (extension == "png")
     return "image/png";
 
   if (extension == "gif")
     return "image/gif";
 
   if (extension == "svg")
     return "image/svg+xml";
 
   if (extension == "woff2")
     return "application/font-woff2";
 
-  CHECK(false) << path;
+  NOTREACHED() << path;
   return "text/plain";
 }
 
 base::MessageLoop* SharedResourcesDataSource::MessageLoopForRequestPath(
     const std::string& path) const {
   return nullptr;
 }
 
 std::string
 SharedResourcesDataSource::GetAccessControlAllowOriginForOrigin(
     const std::string& origin) const {
   // For now we give access only for "chrome://*" origins.
   // According to CORS spec, Access-Control-Allow-Origin header doesn't support
   // wildcards, so we need to set its value explicitly by passing the |origin|
   // back.
   std::string allowed_origin_prefix = kChromeUIScheme;
   allowed_origin_prefix += "://";
   if (origin.find(allowed_origin_prefix) != 0)
     return "null";
   return origin;
 }
 
 }  // namespace content