Moved NavigationManagerImpl serialization out of CRWSessionController.

ios/web/navigation/navigation_manager_impl_unittest.mm

Index: ios/web/navigation/navigation_manager_impl_unittest.mm
diff --git a/ios/web/navigation/navigation_manager_impl_unittest.mm b/ios/web/navigation/navigation_manager_impl_unittest.mm
index 142da93322a1a5f704508b0898f1daff1a66d389..e8ca163354d381589456b4ce43115cf8b66e9a2e 100644
--- a/ios/web/navigation/navigation_manager_impl_unittest.mm
+++ b/ios/web/navigation/navigation_manager_impl_unittest.mm
@@ -28,8 +28,9 @@ void OnNavigationItemCommitted(const LoadCommittedDetails&) override {}
 // Test fixture for NavigationManagerImpl testing.
 class NavigationManagerTest : public PlatformTest {
  protected:
-  NavigationManagerTest()
-      : manager_(new NavigationManagerImpl(&delegate_, &browser_state_)) {
+  NavigationManagerTest() : manager_(new NavigationManagerImpl()) {
+    manager_->SetDelegate(&delegate_);
+    manager_->SetBrowserState(&browser_state_);
     controller_.reset([[CRWSessionController alloc]
            initWithWindowName:nil
                      openerId:nil