Meta: Add and document convenient method to build non-Qt Ladybird chrome

This lets us switch between the AppKit and Qt chromes more easily.

Documentation/BuildInstructionsLadybird.md

@@ -65,12 +65,27 @@ MinGW/MSYS2 are not supported, but may work with sufficient elbow grease. Native
 
 The simplest way to build and run ladybird is via the serenity.sh script:
 
-```
+```bash
 # From /path/to/serenity
 ./Meta/serenity.sh run lagom ladybird
 ./Meta/serenity.sh gdb lagom ladybird
 ```
 
+By default, the above commands will build Ladybird using Qt for the browser chrome. We also support
+the following platform-specific browser chromes:
+
+* [AppKit](https://developer.apple.com/documentation/appkit?language=objc) - The native chrome on macOS.
+
+To build Ladybird using one of these chromes on the appropriate platform, use the following serenity.sh
+commands:
+
+```bash
+# From /path/to/serenity
+./Meta/serenity.sh run lagom ladybird-appkit # Use the AppKit chrome on macOS.
+```
+
+### Disabling Ladybird
+
 Note that running ladybird from the script will change the CMake cache in your Build/lagom build
 directory to always build LibWeb and Ladybird for Lagom when rebuilding SerenityOS using the
 serenity.sh script to run a qemu instance.
@@ -78,7 +93,7 @@ serenity.sh script to run a qemu instance.
 To restore the previous behavior that only builds code generators and tools from Lagom when
 rebuilding serenity, you must modify the CMake cache back to the default.
 
-```
+```bash
 cmake -S Meta/Lagom -B Build/lagom -DENABLE_LAGOM_LADYBIRD=OFF -DENABLE_LAGOM_LIBWEB=OFF -DBUILD_LAGOM=OFF
 ```
 

Meta/serenity.sh

@@ -109,6 +109,15 @@ CMAKE_ARGS+=( "-DSERENITY_TOOLCHAIN=$TOOLCHAIN_TYPE" )
 
 CMD_ARGS=( "$@" )
 
+LADYBIRD_ENABLE_QT=1
+
+if [ "$TARGET" = "lagom" ]; then
+    if [ "${CMD_ARGS[0]}" = "ladybird-appkit" ]; then
+        CMD_ARGS[0]="ladybird"
+        LADYBIRD_ENABLE_QT=0
+    fi
+fi
+
 get_top_dir() {
     git rev-parse --show-toplevel
 }
@@ -129,7 +138,7 @@ is_valid_target() {
     if [ "$TARGET" = "lagom" ]; then
         CMAKE_ARGS+=("-DBUILD_LAGOM=ON")
         if [ "${CMD_ARGS[0]}" = "ladybird" ]; then
-            CMAKE_ARGS+=("-DENABLE_LAGOM_LADYBIRD=ON")
+            CMAKE_ARGS+=("-DENABLE_LAGOM_LADYBIRD=ON" "-DENABLE_QT=${LADYBIRD_ENABLE_QT}")
         fi
         return 0
     fi
@@ -270,11 +279,11 @@ build_target() {
     if [ "$TARGET" = "lagom" ]; then
         # Ensure that all lagom binaries get built, in case user first
         # invoked superbuild for serenity target that doesn't set -DBUILD_LAGOM=ON
-        local EXTRA_CMAKE_ARGS=""
+        local EXTRA_CMAKE_ARGS=()
         if [ "${CMD_ARGS[0]}" = "ladybird" ]; then
-            EXTRA_CMAKE_ARGS="-DENABLE_LAGOM_LADYBIRD=ON"
+            EXTRA_CMAKE_ARGS=("-DENABLE_LAGOM_LADYBIRD=ON" "-DENABLE_QT=${LADYBIRD_ENABLE_QT}")
         fi
-        cmake -S "$SERENITY_SOURCE_DIR/Meta/Lagom" -B "$BUILD_DIR" -DBUILD_LAGOM=ON ${EXTRA_CMAKE_ARGS}
+        cmake -S "$SERENITY_SOURCE_DIR/Meta/Lagom" -B "$BUILD_DIR" -DBUILD_LAGOM=ON "${EXTRA_CMAKE_ARGS[@]}"
     fi
 
     # Get either the environment MAKEJOBS or all processors via CMake
@@ -441,7 +450,7 @@ if [[ "$CMD" =~ ^(build|install|image|copy-src|run|gdb|test|rebuild|recreate|kad
     ensure_target
     case "$CMD" in
         build)
-            build_target "$@"
+            build_target "${CMD_ARGS[@]}"
             ;;
         install)
             build_target
@@ -480,7 +489,7 @@ if [[ "$CMD" =~ ^(build|install|image|copy-src|run|gdb|test|rebuild|recreate|kad
         gdb)
             if [ "$TARGET" = "lagom" ]; then
                 [ $# -ge 1 ] || usage
-                build_target "$@"
+                build_target "${CMD_ARGS[@]}"
                 run_gdb "${CMD_ARGS[@]}"
             else
                 command -v tmux >/dev/null 2>&1 || die "Please install tmux!"
@@ -505,7 +514,7 @@ if [[ "$CMD" =~ ^(build|install|image|copy-src|run|gdb|test|rebuild|recreate|kad
             fi
             ;;
         rebuild)
-            build_target "$@"
+            build_target "${CMD_ARGS[@]}"
             ;;
         recreate)
             ;;
@@ -540,7 +549,7 @@ if [[ "$CMD" =~ ^(build|install|image|copy-src|run|gdb|test|rebuild|recreate|kad
             fi
             ;;
         *)
-            build_target "$CMD" "$@"
+            build_target "$CMD" "${CMD_ARGS[@]}"
             ;;
     esac
 elif [ "$CMD" = "delete" ]; then