[ios] Add a delegate to WebStateList class.

ios/shared/chrome/browser/tabs/web_state_list_unittest.mm

 // Copyright 2017 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.
 
 #import "ios/shared/chrome/browser/tabs/web_state_list.h"
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/supports_user_data.h"
+#import "ios/shared/chrome/browser/tabs/fake_web_state_list_delegate.h"
 #import "ios/shared/chrome/browser/tabs/web_state_list_observer.h"
 #import "ios/web/public/test/fakes/test_navigation_manager.h"
 #import "ios/web/public/test/fakes/test_web_state.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
@@ skipping 112 matching lines @@
 
   int current_item_index_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(FakeNavigationManer);
 };
 
 }  // namespace
 
 class WebStateListTest : public PlatformTest {
  public:
-  WebStateListTest() : web_state_list_(WebStateList::WebStateOwned) {
+  WebStateListTest()
+      : web_state_list_(&web_state_list_delegate_,
+                        WebStateList::WebStateOwned) {
     web_state_list_.AddObserver(&observer_);
   }
 
   ~WebStateListTest() override { web_state_list_.RemoveObserver(&observer_); }
 
  protected:
+  FakeWebStateListDelegate web_state_list_delegate_;
   WebStateList web_state_list_;
   WebStateListTestObserver observer_;
 
   // This method should return std::unique_ptr<> however, due to the complex
   // ownership of Tab, WebStateList currently uses raw pointers. Change this
   // once Tab ownership is sane, see http://crbug.com/546222 for progress.
   web::WebState* CreateWebState(const char* url) {
     auto test_web_state = base::MakeUnique<web::TestWebState>();
     test_web_state->SetCurrentURL(GURL(url));
     test_web_state->SetNavigationManager(
@@ skipping 224 matching lines @@
   EXPECT_EQ(kURL1, web_state_list_.GetWebStateAt(1)->GetVisibleURL().spec());
 }
 
 TEST_F(WebStateListTest, OwnershipBorrowed) {
   bool web_state_was_killed = false;
   auto test_web_state = base::MakeUnique<web::TestWebState>();
   test_web_state->SetUserData(
       &kSupportsUserDataDeathGuardKey,
       base::MakeUnique<SupportsUserDataDeathGuard>(&web_state_was_killed));
 
-  auto web_state_list =
-      base::MakeUnique<WebStateList>(WebStateList::WebStateBorrowed);
+  FakeWebStateListDelegate web_state_list_delegate;
+  auto web_state_list = base::MakeUnique<WebStateList>(
+      &web_state_list_delegate, WebStateList::WebStateBorrowed);
   web_state_list->InsertWebState(0, test_web_state.get(), nullptr);
   EXPECT_FALSE(web_state_was_killed);
 
   web_state_list.reset();
   EXPECT_FALSE(web_state_was_killed);
 }
 
 TEST_F(WebStateListTest, OwnershipOwned) {
   bool web_state_was_killed = false;
   auto test_web_state = base::MakeUnique<web::TestWebState>();
   test_web_state->SetUserData(
       &kSupportsUserDataDeathGuardKey,
       base::MakeUnique<SupportsUserDataDeathGuard>(&web_state_was_killed));
 
-  auto web_state_list =
-      base::MakeUnique<WebStateList>(WebStateList::WebStateOwned);
+  FakeWebStateListDelegate web_state_list_delegate;
+  auto web_state_list = base::MakeUnique<WebStateList>(
+      &web_state_list_delegate, WebStateList::WebStateOwned);
   web_state_list->InsertWebState(0, test_web_state.release(), nullptr);
   EXPECT_FALSE(web_state_was_killed);
 
   web_state_list.reset();
   EXPECT_TRUE(web_state_was_killed);
 }
 
 TEST_F(WebStateListTest, OpenersEmptyList) {
   EXPECT_TRUE(web_state_list_.empty());
 
@@ skipping 110 matching lines @@
             web_state_list_.GetIndexOfLastWebStateOpenedBy(opener, start_index,
                                                            false));
 
   EXPECT_EQ(WebStateList::kInvalidIndex,
             web_state_list_.GetIndexOfNextWebStateOpenedBy(opener, start_index,
                                                            true));
   EXPECT_EQ(WebStateList::kInvalidIndex,
             web_state_list_.GetIndexOfLastWebStateOpenedBy(opener, start_index,
                                                            true));
 }