Refactor creation of SadTabView into a tab helper object

ios/web/public/test/fakes/test_web_state.mm

Index: ios/web/public/test/fakes/test_web_state.mm
diff --git a/ios/web/public/test/fakes/test_web_state.mm b/ios/web/public/test/fakes/test_web_state.mm
index 293473e10266e5fd92d5ab5042c32ff1f3f98912..902c0fa0a958b776bd11f909dc97eaff649b1e3e 100644
--- a/ios/web/public/test/fakes/test_web_state.mm
+++ b/ios/web/public/test/fakes/test_web_state.mm
@@ -23,6 +23,7 @@ TestWebState::TestWebState()
     : browser_state_(nullptr),
       web_usage_enabled_(false),
       is_loading_(false),
+      is_showing_transient_content_view_(false),
       trust_level_(kAbsolute),
       content_is_html_(true) {}
 
@@ -176,6 +177,21 @@ void TestWebState::OnProvisionalNavigationStarted(const GURL& url) {
     observer.ProvisionalNavigationStarted(url);
 }
 
+void TestWebState::OnRenderProcessGone() {
+  for (auto& observer : observers_)
+    observer.RenderProcessGone();
+}
+
+void TestWebState::ShowTransientContentView(CRWContentView* content_view) {
+  if (content_view) {
+    is_showing_transient_content_view_ = true;
+  }
+}
+
+void TestWebState::ClearTransientContentView() {
+  is_showing_transient_content_view_ = false;
+}
+
 void TestWebState::SetCurrentURL(const GURL& url) {
   url_ = url;
 }
@@ -201,4 +217,8 @@ base::WeakPtr<WebState> TestWebState::AsWeakPtr() {
   return base::WeakPtr<WebState>();
 }
 
+bool TestWebState::IsShowingTransientContentView() {
+  return is_showing_transient_content_view_;
+}
+
 }  // namespace web