Last_n: do not save snapshot of custom tabs.

chrome/browser/android/tab_android.cc

Index: chrome/browser/android/tab_android.cc
diff --git a/chrome/browser/android/tab_android.cc b/chrome/browser/android/tab_android.cc
index 1cbed611875d7ab50fee6a896a21f1930341af61..2b838bcc522064448478e1fa8a860e763cd1c708 100644
--- a/chrome/browser/android/tab_android.cc
+++ b/chrome/browser/android/tab_android.cc
@@ -318,6 +318,11 @@ void TabAndroid::OnFaviconUpdated(favicon::FaviconDriver* favicon_driver,
                               gfx::ConvertToJavaBitmap(&favicon));
 }
 
+bool TabAndroid::IsCurrentlyACustomTab() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return Java_Tab_isCurrentlyACustomTab(env, weak_java_tab_.get(env));
+}
+
 void TabAndroid::Destroy(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   delete this;
 }