cloning flutter repo for luci recipes (flutter#21532)

* cloning flutter repo for luci recipes

* rename the file, script does not clone the repo, but reset it to the right commit

* adding the version logging

tools/configure_framework_commit.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+set -e
+set -x
+
+if [[ -z $ENGINE_PATH ]]
+then
+  echo "Please set ENGINE_PATH environment variable."
+  exit 1
+fi
+
+# Go to the engine git repo to get the date of the latest commit.
+cd $ENGINE_PATH/src/flutter
+
+# Get latest commit's time for the engine repo.
+# Use date based on local time otherwise timezones might get mixed.
+LATEST_COMMIT_TIME_ENGINE=`git log -1 --date=local --format="%cd"`
+echo "Latest commit time on engine found as $LATEST_COMMIT_TIME_ENGINE"
+
+if [[ -z $FLUTTER_CLONE_REPO_PATH ]]
+then
+  echo "Please set FLUTTER_CLONE_REPO_PATH environment variable."
+  exit 1
+else
+  cd $FLUTTER_CLONE_REPO_PATH
+fi
+
+# Get the time of the youngest commit older than engine commit.
+# Git log uses commit date not the author date.
+# Before makes the comparison considering the timezone as well.
+COMMIT_NO=`git log --before="$LATEST_COMMIT_TIME_ENGINE" -n 1 | grep commit | cut -d ' ' -f2`
+echo "Using the flutter/flutter commit $COMMIT_NO";
+git reset --hard $COMMIT_NO
+
+# Print out the flutter version for troubleshooting
+$FLUTTER_CLONE_REPO_PATH/bin/flutter --version