diff --git a/.cirrus.yml b/.cirrus.yml
index 5f17dc96e340..21708555b40e 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -6,6 +6,18 @@ env:
   CHANNEL: "master" # Default to master when not explicitly set by a task.
   PLUGIN_TOOL_COMMAND: "dart ./script/tool/bin/flutter_plugin_tools.dart"
 
+install_chrome_linux_template: &INSTALL_CHROME_LINUX
+  env:
+    CHROME_NO_SANDBOX: true
+    CHROME_DOWNLOAD_DIR: /tmp/chromium
+    CHROME_EXECUTABLE: $CHROME_DOWNLOAD_DIR/chrome-linux/chrome
+    CHROMEDRIVER_EXECUTABLE: $CHROME_DOWNLOAD_DIR/chromedriver/chromedriver
+    PATH: $PATH:$CHROME_DOWNLOAD_DIR/chrome-linux
+  install_chromium_script:
+    # Install a pinned version of Chromium and its corresponding ChromeDriver.
+    # Setting CHROME_EXECUTABLE above causes this version to be used for tests.
+    - ./script/install_chromium.sh
+
 tool_setup_template: &TOOL_SETUP_TEMPLATE
   tool_setup_script:
     - .ci/scripts/prepare_tool.sh
@@ -284,16 +296,9 @@ task:
         matrix:
           CHANNEL: "master"
           CHANNEL: "stable"
-        CHROME_NO_SANDBOX: true
-        CHROME_DIR: /tmp/web_chromium/
-        CHROME_EXECUTABLE: $CHROME_DIR/chrome-linux/chrome
-      install_script:
-        # Install a pinned version of Chromium and its corresponding ChromeDriver.
-        # Setting CHROME_EXECUTABLE above causes this version to be used for tests.
-        - ./script/install_chromium.sh "$CHROME_DIR"
+      << : *INSTALL_CHROME_LINUX
       chromedriver_background_script:
-        - cd "$CHROME_DIR"
-        - ./chromedriver/chromedriver --port=4444
+        - $CHROMEDRIVER_EXECUTABLE --port=4444
       build_script:
         - ./script/tool_runner.sh build-examples --web
       drive_script:
diff --git a/script/install_chromium.sh b/script/install_chromium.sh
index 0d360fe98cfe..ed55776a5c19 100755
--- a/script/install_chromium.sh
+++ b/script/install_chromium.sh
@@ -2,41 +2,51 @@
 # Copyright 2013 The Flutter Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
+
+# This script may be run as:
+# $ CHROME_DOWNLOAD_DIR=./whatever script/install_chromium.sh
 set -e
 set -x
 
-readonly TARGET_DIR=$1
+# The target directory where chromium is going to be downloaded
+: "${CHROME_DOWNLOAD_DIR:=/tmp/chromium}" # Default value for the CHROME_DOWNLOAD_DIR env.
 
 # The build of Chromium used to test web functionality.
 #
 # Chromium builds can be located here: https://commondatastorage.googleapis.com/chromium-browser-snapshots/index.html?prefix=Linux_x64/
 #
-# Check: https://github.com/flutter/engine/blob/main/lib/web_ui/dev/browser_lock.yaml
-readonly CHROMIUM_BUILD=929514
+# Check: https://github.com/flutter/engine/blob/master/lib/web_ui/dev/browser_lock.yaml
+: "${CHROMIUM_BUILD:=950363}" # Default value for the CHROMIUM_BUILD env.
+
+# Convenience defaults for CHROME_EXECUTABLE and CHROMEDRIVER_EXECUTABLE. These
+# two values should be set in the environment from CI, so this script can validate
+# that it has completed downloading chrome and driver successfully (and the expected
+# files are executable)
+: "${CHROME_EXECUTABLE:=$CHROME_DOWNLOAD_DIR/chrome-linux/chrome}"
+: "${CHROMEDRIVER_EXECUTABLE:=$CHROME_DOWNLOAD_DIR/chromedriver/chromedriver}"
 
 # The correct ChromeDriver is distributed alongside the chromium build above, as
 # `chromedriver_linux64.zip`, so no need to hardcode any extra info about it.
 readonly DOWNLOAD_ROOT="https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o/Linux_x64%2F${CHROMIUM_BUILD}%2F"
 
 # Install Chromium.
-mkdir "$TARGET_DIR"
-readonly CHROMIUM_ZIP_FILE="$TARGET_DIR/chromium.zip"
+mkdir "$CHROME_DOWNLOAD_DIR"
+readonly CHROMIUM_ZIP_FILE="$CHROME_DOWNLOAD_DIR/chromium.zip"
 wget --no-verbose "${DOWNLOAD_ROOT}chrome-linux.zip?alt=media" -O "$CHROMIUM_ZIP_FILE"
-unzip -q "$CHROMIUM_ZIP_FILE" -d "$TARGET_DIR/"
+unzip -q "$CHROMIUM_ZIP_FILE" -d "$CHROME_DOWNLOAD_DIR/"
 
 # Install ChromeDriver.
-readonly DRIVER_ZIP_FILE="$TARGET_DIR/chromedriver.zip"
+readonly DRIVER_ZIP_FILE="$CHROME_DOWNLOAD_DIR/chromedriver.zip"
 wget --no-verbose "${DOWNLOAD_ROOT}chromedriver_linux64.zip?alt=media" -O "$DRIVER_ZIP_FILE"
-unzip -q "$DRIVER_ZIP_FILE" -d "$TARGET_DIR/"
-# Rename TARGET_DIR/chromedriver_linux64 to the expected TARGET_DIR/chromedriver
-mv -T "$TARGET_DIR/chromedriver_linux64" "$TARGET_DIR/chromedriver"
-
-export CHROME_EXECUTABLE="$TARGET_DIR/chrome-linux/chrome"
+unzip -q "$DRIVER_ZIP_FILE" -d "$CHROME_DOWNLOAD_DIR/"
+# Rename CHROME_DOWNLOAD_DIR/chromedriver_linux64 to the expected CHROME_DOWNLOAD_DIR/chromedriver
+mv -T "$CHROME_DOWNLOAD_DIR/chromedriver_linux64" "$CHROME_DOWNLOAD_DIR/chromedriver"
 
 # Echo info at the end for ease of debugging.
+#
+# exports from this script cannot be used elsewhere in the .cirrus.yml file.
 set +x
 echo
-readonly CHROMEDRIVER_EXECUTABLE="$TARGET_DIR/chromedriver/chromedriver"
 echo "$CHROME_EXECUTABLE"
 "$CHROME_EXECUTABLE" --version
 echo "$CHROMEDRIVER_EXECUTABLE"