Allow using a BrowserViewController without BookmarkModel for testing.

ios/chrome/browser/ui/main/browser_view_wrangler_unittest.mm

 // Copyright 2016 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/chrome/browser/ui/main/browser_view_wrangler.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/mac/scoped_nsobject.h"
-#include "components/bookmarks/test/bookmark_test_helpers.h"
-#include "ios/chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
 #import "ios/chrome/browser/tabs/tab_model.h"
 #import "ios/chrome/browser/ui/browser_view_controller.h"
 #include "ios/web/public/test/test_web_thread_bundle.h"
 #include "testing/platform_test.h"
 
 namespace {
 
 class BrowserViewWranglerTest : public PlatformTest {
  protected:
   BrowserViewWranglerTest() {
     TestChromeBrowserState::Builder test_cbs_builder;
     chrome_browser_state_ = test_cbs_builder.Build();
-    chrome_browser_state_->CreateBookmarkModel(false);
-    bookmarks::BookmarkModel* bookmark_model =
-        ios::BookmarkModelFactory::GetForBrowserState(
-            chrome_browser_state_.get());
-    bookmarks::test::WaitForBookmarkModelToLoad(bookmark_model);
   }
 
-  // SessionWindow, used to create the TabModel, needs to run on the web thread.
   web::TestWebThreadBundle thread_bundle_;
   std::unique_ptr<TestChromeBrowserState> chrome_browser_state_;
 };
 
 TEST_F(BrowserViewWranglerTest, TestInitNilObserver) {
   base::scoped_nsobject<BrowserViewWrangler> wrangler(
       [[BrowserViewWrangler alloc]
           initWithBrowserState:chrome_browser_state_.get()
               tabModelObserver:nil]);
 
   // Test that BVC and tab model are created on demand.
   BrowserViewController* bvc = [wrangler mainBVC];
   EXPECT_NE(bvc, nil);
 
   TabModel* tabModel = [wrangler mainTabModel];
   EXPECT_NE(tabModel, nil);
 
   // Test that once created the BVC and tab model aren't re-created.
   EXPECT_EQ(bvc, [wrangler mainBVC]);
   EXPECT_EQ(tabModel, [wrangler mainTabModel]);
 
   // Test that the OTR objects are (a) OTR and (b) not the same as the non-OTR
   // objects.
   EXPECT_NE(bvc, [wrangler otrBVC]);
   EXPECT_NE(tabModel, [wrangler otrTabModel]);
   EXPECT_TRUE([wrangler otrTabModel].browserState->IsOffTheRecord());
 }
 
 }  // namespace