WebDriver+Friends: Add IPC and plumbing for Element-getting

This extends the IPC calls `get_document_element` and
`query_selector_all` to be usable by the WebDriver. For this the
`WebDriverConnection` provides the same interfaces and takes care of
routing the data through the Browser.

Userland/Applications/Browser/BrowserWindow.cpp

@@ -582,6 +582,14 @@ void BrowserWindow::create_new_tab(URL url, bool activate)
         return active_tab().view().get_session_storage_entries();
     };
 
+    new_tab.on_get_document_element = [this]() {
+        return active_tab().view().get_document_element();
+    };
+
+    new_tab.on_query_selector_all = [this](i32 start_node_id, String const& selector) {
+        return active_tab().view().query_selector_all(start_node_id, selector);
+    };
+
     new_tab.load(url);
 
     dbgln_if(SPAM_DEBUG, "Added new tab {:p}, loading {}", &new_tab, url);

Userland/Applications/Browser/Tab.h

@@ -68,6 +68,8 @@ public:
     Function<Vector<Web::Cookie::Cookie>()> on_get_cookies_entries;
     Function<OrderedHashMap<String, String>()> on_get_local_storage_entries;
     Function<OrderedHashMap<String, String>()> on_get_session_storage_entries;
+    Function<Optional<i32>()> on_get_document_element;
+    Function<Optional<Vector<i32>>(i32 start_node_id, String const&)> on_query_selector_all;
 
     enum class InspectorTarget {
         Document,

Userland/Applications/Browser/WebDriverConnection.cpp

@@ -121,4 +121,26 @@ void WebDriverConnection::update_cookie(Web::Cookie::Cookie const& cookie)
     }
 }
 
+Messages::WebDriverSessionClient::GetDocumentElementResponse WebDriverConnection::get_document_element()
+{
+    dbgln("WebDriverConnection: get_document_element");
+    if (auto browser_window = m_browser_window.strong_ref()) {
+        auto& tab = browser_window->active_tab();
+        if (tab.on_get_document_element)
+            return { tab.on_get_document_element() };
+    }
+    return { {} };
+}
+
+Messages::WebDriverSessionClient::QuerySelectorAllResponse WebDriverConnection::query_selector_all(i32 start_node_id, String const& selector)
+{
+    dbgln("WebDriverConnection: query_selector_all");
+    if (auto browser_window = m_browser_window.strong_ref()) {
+        auto& tab = browser_window->active_tab();
+        if (tab.on_query_selector_all)
+            return { tab.on_query_selector_all(start_node_id, selector) };
+    }
+    return { {} };
+}
+
 }

Userland/Applications/Browser/WebDriverConnection.h

@@ -47,6 +47,8 @@ public:
     virtual Messages::WebDriverSessionClient::GetNamedCookieResponse get_named_cookie(String const& name) override;
     virtual void add_cookie(Web::Cookie::ParsedCookie const&) override;
     virtual void update_cookie(Web::Cookie::Cookie const&) override;
+    virtual Messages::WebDriverSessionClient::GetDocumentElementResponse get_document_element() override;
+    virtual Messages::WebDriverSessionClient::QuerySelectorAllResponse query_selector_all(i32 start_node_id, String const& selector) override;
 
 private:
     WebDriverConnection(NonnullOwnPtr<Core::Stream::LocalSocket> socket, NonnullRefPtr<BrowserWindow> browser_window);

Userland/Applications/Browser/WebDriverSessionClient.ipc

@@ -16,5 +16,7 @@ endpoint WebDriverSessionClient {
     get_named_cookie(String name) => (Optional<Web::Cookie::Cookie> cookie)
     add_cookie(Web::Cookie::ParsedCookie cookie) =|
     update_cookie(Web::Cookie::Cookie cookie) =|
+    get_document_element() => (Optional<i32> document_element_id)
+    query_selector_all(i32 start_node_id, String selector) => (Optional<Vector<i32>> elements_ids)
 
 }

Userland/Libraries/LibWebView/OutOfProcessWebView.cpp

@@ -515,6 +515,16 @@ OrderedHashMap<String, String> OutOfProcessWebView::get_session_storage_entries(
     return client().get_session_storage_entries();
 }
 
+Optional<i32> OutOfProcessWebView::get_document_element()
+{
+    return client().get_document_element();
+}
+
+Optional<Vector<i32>> OutOfProcessWebView::query_selector_all(i32 start_node_id, String const& selector)
+{
+    return client().query_selector_all(start_node_id, selector);
+}
+
 void OutOfProcessWebView::set_content_filters(Vector<String> filters)
 {
     client().async_set_content_filters(filters);

Userland/Libraries/LibWebView/OutOfProcessWebView.h

@@ -58,6 +58,9 @@ public:
     OrderedHashMap<String, String> get_local_storage_entries();
     OrderedHashMap<String, String> get_session_storage_entries();
 
+    Optional<i32> get_document_element();
+    Optional<Vector<i32>> query_selector_all(i32 start_node_id, String const& selector);
+
     void set_content_filters(Vector<String>);
     void set_proxy_mappings(Vector<String> proxies, HashMap<String, size_t> mappings);
     void set_preferred_color_scheme(Web::CSS::PreferredColorScheme);