Clearing Tabs and Observer list when TabModelBase is destroyed.

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelBase.java

 // 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.
 
 package org.chromium.chrome.browser.tabmodel;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.ObserverList;
 import org.chromium.base.TraceEvent;
 import org.chromium.chrome.browser.Tab;
@@ skipping 67 matching lines @@
         for (Tab tab : mTabs) {
             if (tab.isInitialized()) tab.destroy();
         }
 
         mRewoundList.destroy();
 
         if (mNativeTabModelImpl != 0) {
             nativeDestroy(mNativeTabModelImpl);
             mNativeTabModelImpl = 0;
         }
+
+        mTabs.clear();
+        mObservers.clear();
     }
 
     @Override
     public void addObserver(TabModelObserver observer) {
         mObservers.addObserver(observer);
     }
 
     @Override
     public void removeObserver(TabModelObserver observer) {
         mObservers.removeObserver(observer);
@@ skipping 525 matching lines @@
     private boolean isSessionRestoreInProgress() {
         return mModelDelegate.isSessionRestoreInProgress();
     }
 
     private native long nativeInit(boolean isIncognito);
     private native void nativeDestroy(long nativeTabModelBase);
     private native void nativeBroadcastSessionRestoreComplete(long nativeTabModelBase);
     private native Profile nativeGetProfileAndroid(long nativeTabModelBase);
     private native void nativeTabAddedToModel(long nativeTabModelBase, Tab tab);
 }