Coverity: pass ContentSettingsPattern by const ref

chrome/browser/content_settings/host_content_settings_map.h

 // Copyright (c) 2011 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.
 
 // Maps hostnames to custom content settings.  Written on the UI thread and read
 // on any thread.  One instance per profile.
 
 #ifndef CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_
 #pragma once
@@ skipping 148 matching lines @@
                                       ContentSettingsType content_type);
 
   // Detaches the HostContentSettingsMap from all Profile-related objects like
   // PrefService. This methods needs to be called before destroying the Profile.
   // Afterwards, none of the methods above that should only be called on the UI
   // thread should be called anymore.
   void ShutdownOnUIThread();
 
   // content_settings::Observer implementation.
   virtual void OnContentSettingChanged(
-      ContentSettingsPattern primary_pattern,
-      ContentSettingsPattern secondary_pattern,
+      const ContentSettingsPattern& primary_pattern,
+      const ContentSettingsPattern& secondary_pattern,
       ContentSettingsType content_type,
       std::string resource_identifier) OVERRIDE;
 
   // Returns true if we should allow all content types for this URL.  This is
   // true for various internal objects like chrome:// URLs, so UI and other
   // things users think of as "not webpages" don't break.
   static bool ShouldAllowAllContent(const GURL& primary_url,
                                     const GURL& secondary_url,
                                     ContentSettingsType content_type);
 
@@ skipping 42 matching lines @@
   // Content setting providers.
   ProviderMap content_settings_providers_;
 
   // Used around accesses to the following objects to guarantee thread safety.
   mutable base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(HostContentSettingsMap);
 };
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_