[ios] Adds a provider API for AudioSessionController.

ios/public/provider/chrome/browser/chrome_browser_provider.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 IOS_PUBLIC_PROVIDER_CHROME_BROWSER_CHROME_BROWSER_PROVIDER_H_
 #define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_CHROME_BROWSER_PROVIDER_H_
 
 #include <CoreGraphics/CoreGraphics.h>
 #import <Foundation/Foundation.h>
 #include <stddef.h>
@@ skipping 42 matching lines @@
 
 namespace ios {
 
 class ChromeBrowserProvider;
 class ChromeBrowserState;
 class ChromeIdentityService;
 class GeolocationUpdaterProvider;
 class SigninResourcesProvider;
 class LiveTabContextProvider;
 class UpdatableResourceProvider;
+class VoiceSearchProvider;
 
 // Setter and getter for the provider. The provider should be set early, before
 // any browser code is called.
 void SetChromeBrowserProvider(ChromeBrowserProvider* provider);
 ChromeBrowserProvider* GetChromeBrowserProvider();
 
 // A class that allows embedding iOS-specific functionality in the
 // ios_chrome_browser target.
 class ChromeBrowserProvider {
  public:
@@ skipping 61 matching lines @@
   // is not yet available through web::WebState.
   // TODO(rohitrao): Change from |id| to |Tab*| once Tab is moved into the
   // Chromium tree.
   virtual void AttachTabHelpers(web::WebState* web_state, id tab) const;
 
   // Returns whether safe browsing is enabled. See the comment on
   // metrics_services_manager_client.h for details on |on_update_callback|.
   virtual bool IsSafeBrowsingEnabled(const base::Closure& on_update_callback);
 
   // Returns the list of available voice search languages.
+  // TODO(rohitrao): Remove once callers are going through VoiceSearchProvider.
   virtual NSArray* GetAvailableVoiceSearchLanguages() const;
 
+  // Returns an instance of the voice search provider, if one exists.
+  virtual VoiceSearchProvider* GetVoiceSearchProvider();

[sdefresne, 2016/10/18 22:19:43]

This method should be const.

[rohitrao (ping after 24h), 2016/10/18 23:30:44]

Done.

+
   // Returns the SyncedWindowDelegatesGetter implementation.
   virtual std::unique_ptr<sync_sessions::SyncedWindowDelegatesGetter>
   CreateSyncedWindowDelegatesGetter(ios::ChromeBrowserState* browser_state);
 };
 
 }  // namespace ios
 
 #endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_CHROME_BROWSER_PROVIDER_H_