WebContent: Remove a bunch of unused includes from PageHost

Mostly just to narrow down where HAS_ACCELERATED_GRAPHICS is used, to
make it easier to see where it needs to be defined by the build system.

Userland/Services/WebContent/PageHost.cpp

@@ -6,27 +6,12 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include "PageHost.h"
-#include "ConnectionFromClient.h"
-#include "PageClient.h"
-#include <LibGfx/ShareableBitmap.h>
-#include <LibGfx/SystemTheme.h>
-#include <LibWeb/CSS/SystemColor.h>
-#include <LibWeb/Cookie/ParsedCookie.h>
-#include <LibWeb/HTML/BrowsingContext.h>
 #include <LibWeb/HTML/TraversableNavigable.h>
-#include <LibWeb/Layout/Viewport.h>
-#include <LibWeb/Painting/PaintableBox.h>
-#include <LibWeb/Painting/PaintingCommandExecutorCPU.h>
-#include <LibWeb/Painting/ViewportPaintable.h>
-#include <LibWeb/Platform/Timer.h>
-#include <WebContent/WebContentClientEndpoint.h>
+#include <WebContent/ConnectionFromClient.h>
+#include <WebContent/PageClient.h>
+#include <WebContent/PageHost.h>
 #include <WebContent/WebDriverConnection.h>
 
-#ifdef HAS_ACCELERATED_GRAPHICS
-#    include <LibWeb/Painting/PaintingCommandExecutorGPU.h>
-#endif
-
 namespace WebContent {
 
 PageHost::PageHost(ConnectionFromClient& client)

Userland/Services/WebContent/PageHost.h

@@ -8,16 +8,13 @@
 
 #pragma once
 
-#include <LibAccelGfx/Forward.h>
-#include <LibGfx/Rect.h>
-#include <LibWeb/Page/Page.h>
-#include <LibWeb/PixelUnits.h>
+#include <AK/Function.h>
+#include <AK/HashMap.h>
+#include <AK/NonnullOwnPtr.h>
 #include <WebContent/Forward.h>
 
 namespace WebContent {
 
-class ConnectionFromClient;
-
 class PageHost {
     AK_MAKE_NONCOPYABLE(PageHost);
     AK_MAKE_NONMOVABLE(PageHost);