[IOSTabRefactoring] Replace tab.view by webState.GetView()

This CL to prepare for removing -view method from Tab

Bug: 899832
Change-Id: Iebe22114e1b478bb41e418e66c5ba5b85109166e
Reviewed-on: https://chromium-review.googlesource.com/c/1318178Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Mohammad Refaat <mrefaat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605437}

ios/chrome/browser/tabs/tab.mm

@@ -420,7 +420,11 @@ NSString* const kTabUrlKey = @"url";
     _openInController = [[OpenInController alloc]
         initWithURLLoaderFactory:_browserState->GetSharedURLLoaderFactory()
                    webController:self.webController];
-    _openInController.baseView = self.view;
+    // If the tab was evicted before, It should have been loaded already before
+    // starting the open-in controller.
+    DCHECK(!self.webState->IsEvicted());
+    self.webState->GetNavigationManager()->LoadIfNecessary();
+    _openInController.baseView = self.webState->GetView();
   }
   return _openInController;
 }

ios/chrome/browser/tabs/tab_unittest.mm

@@ -200,6 +200,7 @@ class TabTest : public BlockCleanupTest,
       OCMStub([mock_web_controller_ webViewNavigationProxy])
           .andReturn(mock_web_view_);
     }
+    OCMStub([mock_web_controller_ isViewAlive]).andReturn(YES);
 
     web::WebState::CreateParams create_params(browser_state);
     web_state_impl_ = std::make_unique<web::WebStateImpl>(create_params);