e2e test for transformer (webdriver + pub serve)

tool/get_chrome_canary.sh

Index: tool/get_chrome_canary.sh
diff --git a/tool/get_chrome_canary.sh b/tool/get_chrome_canary.sh
index 6d6a7a93c90e242fffdcbe6e8fad1cd2303be050..8f023138ef83392e01e76f805eaae8ba10286507 100755
--- a/tool/get_chrome_canary.sh
+++ b/tool/get_chrome_canary.sh
@@ -10,12 +10,32 @@
 
 set -eu
 
-readonly CHROME_URL=https://storage.googleapis.com/chromium-browser-snapshots/Linux_x64
-readonly CHROME_REV=$(curl -s ${CHROME_URL}/LAST_CHANGE)
+readonly CHROME_SNAPSHOTS=https://storage.googleapis.com/chromium-browser-snapshots
+declare CHROME_URL
+declare CHROME_NAME
+declare CHROME_RELATIVE_BIN
+
+if [[ "$OSTYPE" == "linux"* ]]; then
+  CHROME_URL=$CHROME_SNAPSHOTS/Linux_x64
+  CHROME_NAME=chrome-linux
+  CHROME_RELATIVE_BIN=chrome
+elif [[ "$OSTYPE" == "darwin"* ]]; then
+  CHROME_URL=$CHROME_SNAPSHOTS/Mac
+  CHROME_NAME=chrome-mac
+  CHROME_RELATIVE_BIN=Chromium.app/Contents/MacOS/Chromium
+elif [[ "$OSTYPE" == "cygwin" ]]; then
+  CHROME_URL=$CHROME_SNAPSHOTS/Win
+  CHROME_NAME=chrome-win32
+  CHROME_RELATIVE_BIN=chrome.exe
+else
+  echo "Unknown platform: $OSTYPE" >&2
+  exit 1
+fi
 
 readonly CHROME_CANARY_DIR=$HOME/.chrome/canary
-readonly CHROME_CANARY_BIN=$CHROME_CANARY_DIR/chrome-linux/chrome
+readonly CHROME_CANARY_BIN=$CHROME_CANARY_DIR/$CHROME_NAME/$CHROME_RELATIVE_BIN
 readonly CHROME_CANARY_REV_FILE=$CHROME_CANARY_DIR/VERSION
+readonly CHROME_REV=$(curl -s ${CHROME_URL}/LAST_CHANGE)
 
 function getCanary() {
   local existing_version=""
@@ -29,7 +49,7 @@ function getCanary() {
     rm -fR $CHROME_CANARY_DIR
     mkdir -p $CHROME_CANARY_DIR
 
-    local file=chrome-linux.zip
+    local file=$CHROME_NAME.zip
     curl ${CHROME_URL}/${CHROME_REV}/$file -o $file
     unzip $file -d $CHROME_CANARY_DIR
     rm $file
@@ -39,4 +59,4 @@ function getCanary() {
 
 getCanary >&2
 
-echo $CHROME_CANARY_BIN
+echo $CHROME_CANARY_BIN