fix tab restore service crash

chrome/browser/sessions/tab_restore_service_browsertest.cc

 // Copyright (c) 2011 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.
 
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/sessions/session_types.h"
 #include "chrome/browser/sessions/session_service.h"
 #include "chrome/browser/sessions/session_service_factory.h"
 #include "chrome/browser/sessions/tab_restore_service.h"
@@ skipping 598 matching lines @@
   tab->navigations.push_back(navigation);
   tab->navigations.push_back(navigation);
   service_->entries_.push_front(tab);
   EXPECT_EQ(max_entries, service_->entries_.size());
   service_->PruneEntries();
   EXPECT_EQ(max_entries, service_->entries_.size());
   EXPECT_EQ(GURL(chrome::kChromeUINewTabURL),
       static_cast<Tab*>(service_->entries_.front())->
           navigations[1].virtual_url());
 }
+
+// Regression test for crbug.com/106082
+TEST_F(TabRestoreServiceTest, PruneIsCalled) {
+  CreateSessionServiceWithOneWindow(false);
+
+  SessionServiceFactory::GetForProfile(profile())->
+      MoveCurrentSessionToLastSession();
+
+  profile()->set_restored_last_session(true);
+
+  const size_t max_entries = TabRestoreService::kMaxEntries;
+  for (size_t i = 0; i < max_entries + 5; i++) {
+    NavigateAndCommit(GURL(StringPrintf("http://%d", static_cast<int>(i))));
+    service_->CreateHistoricalTab(&controller(), -1);
+  }
+
+  EXPECT_EQ(max_entries, service_->entries_.size());
+  // This should not crash.
+  service_->LoadTabsFromLastSession();
+  EXPECT_EQ(max_entries, service_->entries_.size());
+}