LibWeb: Add Internals.middleClick

This simulates click of the middle mouse button, which is necessary for
testing whether the `auxevent` fires correctly.

(cherry picked from commit 728fca1b1ffd8b472bc8524e5e8ec8443de011a5)

Userland/Libraries/LibWeb/Internals/Internals.cpp

@@ -77,10 +77,20 @@ void Internals::commit_text()
 }
 
 void Internals::click(double x, double y)
+{
+    click(x, y, UIEvents::MouseButton::Primary);
+}
+
+void Internals::middle_click(double x, double y)
+{
+    click(x, y, UIEvents::MouseButton::Middle);
+}
+
+void Internals::click(double x, double y, UIEvents::MouseButton button)
 {
     auto& page = global_object().browsing_context()->page();
-    page.handle_mousedown({ x, y }, { x, y }, 1, 0, 0);
-    page.handle_mouseup({ x, y }, { x, y }, 1, 0, 0);
+    page.handle_mousedown({ x, y }, { x, y }, button, 0, 0);
+    page.handle_mouseup({ x, y }, { x, y }, button, 0, 0);
 }
 
 void Internals::move_pointer_to(double x, double y)

Userland/Libraries/LibWeb/Internals/Internals.h

@@ -8,6 +8,7 @@
 
 #include <LibWeb/Bindings/PlatformObject.h>
 #include <LibWeb/Internals/InternalAnimationTimeline.h>
+#include <LibWeb/UIEvents/MouseButton.h>
 
 namespace Web::Internals {
 
@@ -27,6 +28,7 @@ public:
     void commit_text();
 
     void click(double x, double y);
+    void middle_click(double x, double y);
     void move_pointer_to(double x, double y);
     void wheel(double x, double y, double delta_x, double delta_y);
 
@@ -37,6 +39,8 @@ public:
 private:
     explicit Internals(JS::Realm&);
     virtual void initialize(JS::Realm&) override;
+
+    void click(double x, double y, UIEvents::MouseButton);
 };
 
 }

Userland/Libraries/LibWeb/Internals/Internals.idl

@@ -13,6 +13,7 @@ interface Internals {
     undefined commitText();
 
     undefined click(double x, double y);
+    undefined middleClick(double x, double y);
     undefined movePointerTo(double x, double y);
     undefined wheel(double x, double y, double deltaX, double deltaY);