LibWeb: Misc. cleanup of code

Some things I came across while working on a bugfix. No functional
changes.

Author: gmta

Libraries/LibWeb/Painting/ScrollState.h

@@ -6,7 +6,6 @@
 
 #pragma once
 
-#include <AK/NonnullOwnPtr.h>
 #include <LibWeb/Painting/ScrollFrame.h>
 
 namespace Web::Painting {

Libraries/LibWeb/SVG/SVGDecodedImageData.cpp

@@ -105,8 +105,7 @@ RefPtr<Gfx::Bitmap> SVGDecodedImageData::render(Gfx::IntSize size) const
     if (!display_list)
         return {};
 
-    auto painting_command_executor_type = m_page_client->display_list_player_type();
-    switch (painting_command_executor_type) {
+    switch (m_page_client->display_list_player_type()) {
     case DisplayListPlayerType::SkiaGPUIfAvailable:
     case DisplayListPlayerType::SkiaCPU: {
         auto painting_surface = Gfx::PaintingSurface::wrap_bitmap(*bitmap);

Libraries/LibWeb/SVG/SVGGradientElement.h

@@ -7,7 +7,6 @@
 #pragma once
 
 #include <AK/IterationDecision.h>
-#include <LibGfx/PaintStyle.h>
 #include <LibWeb/Painting/PaintStyle.h>
 #include <LibWeb/SVG/AttributeParser.h>
 #include <LibWeb/SVG/SVGElement.h>

Libraries/LibWeb/SVG/SVGLinearGradientElement.cpp

@@ -114,13 +114,12 @@ NumberPercentage SVGLinearGradientElement::end_y_impl(HashTable<SVGGradientEleme
 
 Optional<Painting::PaintStyle> SVGLinearGradientElement::to_gfx_paint_style(SVGPaintContext const& paint_context) const
 {
-    auto units = gradient_units();
     // FIXME: Resolve percentages properly
     Gfx::FloatPoint start_point {};
     Gfx::FloatPoint end_point {};
 
     // https://svgwg.org/svg2-draft/pservers.html#LinearGradientElementGradientUnitsAttribute
-    if (units == GradientUnits::ObjectBoundingBox) {
+    if (gradient_units() == GradientUnits::ObjectBoundingBox) {
         // If gradientUnits="objectBoundingBox", the user coordinate system for attributes ‘x1’, ‘y1’, ‘x2’ and ‘y2’
         // is established using the bounding box of the element to which the gradient is applied (see Object bounding
         // box units) and then applying the transform specified by attribute ‘gradientTransform’. Percentages represent