Simplify tool_runner.sh

Author: stuartmorgan-g

script/tool_runner.sh

@@ -5,19 +5,18 @@
 
 set -e
 
+# WARNING! Do not remove this script, or change its behavior, unless you have
+# verified that it will not break the flutter/flutter analysis run of this
+# repository: https://github.com/flutter/flutter/blob/master/dev/bots/test.dart
+
 readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null && pwd)"
 readonly REPO_DIR="$(dirname "$SCRIPT_DIR")"
+readonly TOOL_PATH="$REPO_DIR/script/tool/bin/flutter_plugin_tools.dart"
 
-# Runs the plugin tools from the in-tree source.
-function plugin_tools() {
-  (pushd "$REPO_DIR/script/tool" && dart pub get && popd) >/dev/null
-  dart run "$REPO_DIR/script/tool/bin/flutter_plugin_tools.dart" "$@"
-}
-
-ACTIONS=("$@")
-
-# This has to be turned into a list and then split out to the command line,
-# otherwise it gets treated as a single argument.
-PLUGIN_SHARDING=($PLUGIN_SHARDING)
+# Ensure that the tool dependencies have been fetched.
+(pushd "$REPO_DIR/script/tool" && dart pub get && popd) >/dev/null
 
-(cd "$REPO_DIR" && plugin_tools "${ACTIONS[@]}" --packages-for-branch ${PLUGIN_SHARDING[@]})
+# The tool expects to be run from the repo root.
+cd "$REPO_DIR"
+# Run from the in-tree source.
+dart run "$TOOL_PATH" "$@" --packages-for-branch $PLUGIN_SHARDING