Match Pepper UMA histograms by prefix

chrome/renderer/pepper/pepper_uma_host.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 CHROME_RENDERER_PEPPER_PEPPER_UMA_HOST_H_
 #define CHROME_RENDERER_PEPPER_PEPPER_UMA_HOST_H_
 
 #include <set>
 #include <string>
 
@@ skipping 48 matching lines @@
       ppapi::host::HostMessageContext* context,
       const std::string& name,
       int32_t sample,
       int32_t boundary_value);
 
   const GURL document_url_;
   bool is_plugin_in_process_;
 
   // Set of origins that can use UMA private APIs from NaCl.
   std::set<std::string> allowed_origins_;
-  // Set of histograms that can be used from this interface.
-  std::set<std::string> allowed_histograms_;
+  // Set of hashed histogram prefixes that can be used from this interface.
+  std::set<std::string> allowed_histogram_prefixes_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperUMAHost);
 };
 
 #endif  // CHROME_RENDERER_PEPPER_PEPPER_UMA_HOST_H_