Make availability of hotword hardware known to hotword component extension.

chrome/browser/search/hotword_service.h

 // Copyright 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 CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_
 #define CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 46 matching lines @@
     ~HotwordWebstoreInstaller() override {}
   };
 
   // Returns true if the hotword supports the current system language.
   static bool DoesHotwordSupportLanguage(Profile* profile);
 
   // Always returns true.
   // TODO(amistry): Remove this.
   static bool IsExperimentalHotwordingEnabled();
 
+  // Returns true if hotwording hardware is available.
+  static bool IsHotwordHardwareAvailable();
+
   explicit HotwordService(Profile* profile);
   ~HotwordService() override;
 
   // Overridden from ExtensionRegisterObserver:
   void OnExtensionInstalled(content::BrowserContext* browser_context,
                             const extensions::Extension* extension,
                             bool is_update) override;
   void OnExtensionUninstalled(content::BrowserContext* browser_context,
                               const extensions::Extension* extension,
                               extensions::UninstallReason reason) override;
@@ skipping 143 matching lines @@
 
   // The WeakPtrFactory should be the last member, so the weak pointer
   // gets invalidated before the destructors for other members run,
   // to avoid callbacks into a half-destroyed object.
   base::WeakPtrFactory<HotwordService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HotwordService);
 };
 
 #endif  // CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_