[Navigation Experiment] Add WKBasedNavigationManagerImpl.

ios/web/navigation/legacy_navigation_manager_impl.mm

Index: ios/web/navigation/legacy_navigation_manager_impl.mm
diff --git a/ios/web/navigation/legacy_navigation_manager_impl.mm b/ios/web/navigation/legacy_navigation_manager_impl.mm
index ad44adc27ecfca0aeede9bf2ba0d012eb4a8dc54..ecbbe8c2d2096e335694a33849843b1b0d988bef 100644
--- a/ios/web/navigation/legacy_navigation_manager_impl.mm
+++ b/ios/web/navigation/legacy_navigation_manager_impl.mm
@@ -40,37 +40,6 @@ bool AreURLsInPageNavigation(const GURL& existing_url, const GURL& new_url) {
 
 namespace web {
 
-NavigationManager::WebLoadParams::WebLoadParams(const GURL& url)
-    : url(url),
-      transition_type(ui::PAGE_TRANSITION_LINK),
-      user_agent_override_option(UserAgentOverrideOption::INHERIT),
-      is_renderer_initiated(false),
-      post_data(nil) {}
-
-NavigationManager::WebLoadParams::~WebLoadParams() {}
-
-NavigationManager::WebLoadParams::WebLoadParams(const WebLoadParams& other)
-    : url(other.url),
-      referrer(other.referrer),
-      transition_type(other.transition_type),
-      user_agent_override_option(other.user_agent_override_option),
-      is_renderer_initiated(other.is_renderer_initiated),
-      extra_headers([other.extra_headers copy]),
-      post_data([other.post_data copy]) {}
-
-NavigationManager::WebLoadParams& NavigationManager::WebLoadParams::operator=(
-    const WebLoadParams& other) {
-  url = other.url;
-  referrer = other.referrer;
-  is_renderer_initiated = other.is_renderer_initiated;
-  transition_type = other.transition_type;
-  user_agent_override_option = other.user_agent_override_option;
-  extra_headers.reset([other.extra_headers copy]);
-  post_data.reset([other.post_data copy]);
-
-  return *this;
-}
-
 LegacyNavigationManagerImpl::LegacyNavigationManagerImpl()
     : delegate_(nullptr), browser_state_(nullptr) {}