Last_n: do not save snapshot of custom tabs.

chrome/browser/android/tab_android.h

 // Copyright (c) 2012 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_TAB_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_TAB_ANDROID_H_
 
 #include <jni.h>
 #include <stdint.h>
 
@@ skipping 118 matching lines @@
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override;
 
   // Overridden from favicon::FaviconDriverObserver:
   void OnFaviconUpdated(favicon::FaviconDriver* favicon_driver,
                         NotificationIconType notification_icon_type,
                         const GURL& icon_url,
                         bool icon_url_changed,
                         const gfx::Image& image) override;
 
+  // Returns true if this tab is currently presented in the context of custom
+  // tabs. Tabs can be moved between different activities so the returned value
+  // might change over the lifetime of the tab.
+  bool IsCurrentlyACustomTab();
+
   // Methods called from Java via JNI -----------------------------------------
 
   void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
   void InitWebContents(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
       jboolean incognito,
       const base::android::JavaParamRef<jobject>& jweb_contents,
       const base::android::JavaParamRef<jobject>& jweb_contents_delegate,
       const base::android::JavaParamRef<jobject>& jcontext_menu_populator);
@@ skipping 123 matching lines @@
 
   std::unique_ptr<browser_sync::SyncedTabDelegateAndroid> synced_tab_delegate_;
 
   std::string webapp_manifest_scope_;
   bool embedded_media_experience_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(TabAndroid);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_TAB_ANDROID_H_