[ios] Adds protocols for voice search.

ios/public/provider/chrome/browser/voice/voice_search_bar.h

+// Copyright 2016 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_VOICE_VOICE_SEARCH_BAR_H_
+#define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_VOICE_VOICE_SEARCH_BAR_H_
+
+#import <Foundation/Foundation.h>
+
+@protocol VoiceSearchBarDelegate;
+
+// Protocol used by bottom toolbars containing a button to launch VoiceSearch.
+@protocol VoiceSearchBar<NSObject>
+
+// The VoiceSearchBar's delegate.
+@property(nonatomic, assign) id<VoiceSearchBarDelegate> voiceSearchBarDelegate;
+
+// Animates the view up from the bottom of the its superview so that it's
+// visible or down so that it's no longer visible.
+- (void)animateToBecomeVisible:(BOOL)visible;
+
+// Sets necessary state to prepare for presenting voice search.
+- (void)prepareToPresentVoiceSearch;
+
+@end
+
+// The delegate protocol for VoiceSearchBar.
+@protocol VoiceSearchBarDelegate
+
+// Returns whether Text To Speech is enabled for |voiceSearchBar|.
+- (BOOL)isTTSEnabledForVoiceSearchBar:(id<VoiceSearchBar>)voiceSearchBar;
+
+// Called to notify the delegate that the state of |voiceSearchBar|'s
+// VoiceSearch button appearance has been updated.
+- (void)voiceSearchBarDidUpdateButtonState:(id<VoiceSearchBar>)voiceSearchBar;
+
+@end
+
+#endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_VOICE_VOICE_SEARCH_BAR_H_