Revert of Enable HTMLMediaElement@autoplay on Android

chrome/android/java/src/org/chromium/chrome/browser/Tab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/Tab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/Tab.java b/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
index 50f8b6cb35fde0da8e6ed80a1679875d79effd10..cca0ac6dc0fbd114bef15cd4a72ebf978e0122b0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/Tab.java
@@ -121,6 +121,7 @@
     // Content layer Observers and Delegates
     private ContentViewClient mContentViewClient;
     private WebContentsObserverAndroid mWebContentsObserver;
+    private VoiceSearchTabHelper mVoiceSearchTabHelper;
     private TabChromeWebContentsDelegateAndroid mWebContentsDelegate;
     private DomDistillerFeedbackReporter mDomDistillerFeedbackReporter;
 
@@ -794,6 +795,7 @@
 
         mWebContentsDelegate = createWebContentsDelegate();
         mWebContentsObserver = new TabWebContentsObserverAndroid(mContentViewCore.getWebContents());
+        mVoiceSearchTabHelper = new VoiceSearchTabHelper(mContentViewCore.getWebContents());
 
         if (mContentViewClient != null) mContentViewCore.setContentViewClient(mContentViewClient);
 
@@ -960,6 +962,7 @@
         mContentViewCore = null;
         mWebContentsDelegate = null;
         mWebContentsObserver = null;
+        mVoiceSearchTabHelper = null;
 
         assert mNativeTabAndroid != 0;
         nativeDestroyWebContents(mNativeTabAndroid, deleteNativeWebContents);