Break apart the TabModelBase's JNI calls into its own class

chrome/browser/ui/android/tab_model/tab_model_base.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_UI_ANDROID_TAB_MODEL_TAB_MODEL_BASE_H_
 #define CHROME_BROWSER_UI_ANDROID_TAB_MODEL_TAB_MODEL_BASE_H_
 
 #include <jni.h>
 #include <vector>
 
@@ skipping 10 matching lines @@
 class WebContents;
 }
 
 // Native representation of TabModelBase which provides access to information
 // about a tabstrip to native code and could potentially be used in place of
 // Browser for some functionality in Clank.
 class TabModelBase : public TabModel {
  public:
   TabModelBase(JNIEnv* env, jobject obj, Profile* profile);
   void Destroy(JNIEnv* env, jobject obj);
+  virtual ~TabModelBase();
 
   // Called by JNI
   base::android::ScopedJavaLocalRef<jobject> GetProfileAndroid(JNIEnv* env,
                                                                jobject obj);
   void TabAddedToModel(JNIEnv* env, jobject obj, jobject jtab);
 
   // TabModel:
   virtual int GetTabCount() const OVERRIDE;
   virtual int GetActiveIndex() const OVERRIDE;
   virtual content::WebContents* GetWebContentsAt(int index) const OVERRIDE;
   virtual TabAndroid* GetTabAt(int index) const OVERRIDE;
 
   virtual void SetActiveIndex(int index) OVERRIDE;
   virtual void CloseTabAt(int index) OVERRIDE;
 
   virtual void CreateTab(content::WebContents* web_contents,
                          int parent_tab_id) OVERRIDE;
   virtual content::WebContents* CreateNewTabForDevTools(
       const GURL& url) OVERRIDE;
 
   // Return true if we are currently restoring sessions asynchronously.
   virtual bool IsSessionRestoreInProgress() const OVERRIDE;
 
   // Instructs the TabModel to broadcast a notification that all tabs are now
   // loaded from storage.
   void BroadcastSessionRestoreComplete(JNIEnv* env, jobject obj);
 
- private:
-  virtual ~TabModelBase();
-
+ protected:
   JavaObjectWeakGlobalRef java_object_;
 };
 
 // Register the Tab's native methods through jni.
 bool RegisterTabModelBase(JNIEnv* env);
 
 #endif  // CHROME_BROWSER_UI_ANDROID_TAB_MODEL_TAB_MODEL_BASE_H_