GOOGLE_CHROME_SHIM now responds to --version and --product-version. (h…

…eroku#73)

This change adds out-of-the-box compatibility with the webdrivers gem, which apparently quite a few Heroku users are using. Currently, the users have to use a workaround in their project to get the Chrome version from $GOOGLE_CHROME_BIN, so that webdrivers can download the appropriate version of chromedriver, and then switch back to $GOOGLE_CHROME_SHIM to launch Chrome.

See titusfortner/webdrivers#40, titusfortner/webdrivers#72, and titusfortner/webdrivers#134.

This simple change will provide the convenience of not needing any hacks to make the two work :).

bin/compile

@@ -171,7 +171,13 @@ BIN_DIR=$BUILD_DIR/.apt/usr/bin
 rm $BIN_DIR/$SHIM
 cat <<EOF >$BIN_DIR/$SHIM
 #!/usr/bin/env bash
-exec \$HOME/.apt/opt/google/$BIN --headless --no-sandbox --disable-gpu --remote-debugging-port=9222 \$@
+if [ $1 = "--version" ]; then
+  exec \$HOME/.apt/opt/google/$BIN --version
+elif [ $1 = "--product-version" ]; then
+  exec \$HOME/.apt/opt/google/$BIN --product-version
+else
+  exec \$HOME/.apt/opt/google/$BIN --headless --no-sandbox --disable-gpu --remote-debugging-port=9222 \$@
+fi
 EOF
 chmod +x $BIN_DIR/$SHIM
 cp $BIN_DIR/$SHIM $BIN_DIR/google-chrome