Make VoiceSearchTabHelper a purely native object

chrome/browser/android/voice_search_tab_helper.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_BROWSER_ANDROID_VOICE_SEARCH_TAB_HELPER_H_
 #define CHROME_BROWSER_ANDROID_VOICE_SEARCH_TAB_HELPER_H_
 
-#include "base/android/jni_android.h"
+#include "base/macros.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
 
-bool RegisterVoiceSearchTabHelper(JNIEnv* env);
+// Tab helper to toggle media autoplay for voice URL searches.
+class VoiceSearchTabHelper
+    : public content::WebContentsObserver,
+      public content::WebContentsUserData<VoiceSearchTabHelper> {
+ public:
+  ~VoiceSearchTabHelper() override;
+
+  // content::WebContentsObserver overrides.
+  void NavigationEntryCommitted(
+      const content::LoadCommittedDetails& load_details) override;
+
+ private:
+  explicit VoiceSearchTabHelper(content::WebContents* contents);
+  friend class content::WebContentsUserData<VoiceSearchTabHelper>;
+
+  bool gesture_requirement_for_playback_disabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(VoiceSearchTabHelper);
+};
 
 #endif  // CHROME_BROWSER_ANDROID_VOICE_SEARCH_TAB_HELPER_H_