iostest.bash: do not restart device by default

This is friendlier for manual runs and personal devices.
Builders will pass -restart.

Fixes #10333.

Change-Id: Ia64c8f1660e275b5a1543d7f81f5f5efb623182f
Reviewed-on: https://go-review.googlesource.com/8870Reviewed-by: David Crawshaw <crawshaw@golang.org>

src/iostest.bash

@@ -28,21 +28,23 @@ if [ "$GOARCH" == "arm" ]; then
 	export GOARM=7
 fi
 
-# Reboot to make sure previous runs do not interfere with the current run.
-# It is reasonably easy for a bad program leave an iOS device in an
-# almost unusable state.
-idevicediagnostics restart
-# Initial sleep to make sure we are restarting before we start polling.
-sleep 30
-# Poll until the device has restarted.
-until idevicediagnostics diagnostics; do
-	# TODO(crawshaw): replace with a test app using go_darwin_arm_exec.
-	echo "waiting for idevice to come online"
-	sleep 10
-done
-# Diagnostics are reported during boot before the device can start an
-# app. Wait a little longer before trying to use the device.
-sleep 30
+if [ "$1" == "-restart" ]; then
+	# Reboot to make sure previous runs do not interfere with the current run.
+	# It is reasonably easy for a bad program leave an iOS device in an
+	# almost unusable state.
+	idevicediagnostics restart
+	# Initial sleep to make sure we are restarting before we start polling.
+	sleep 30
+	# Poll until the device has restarted.
+	until idevicediagnostics diagnostics; do
+		# TODO(crawshaw): replace with a test app using go_darwin_arm_exec.
+		echo "waiting for idevice to come online"
+		sleep 10
+	done
+	# Diagnostics are reported during boot before the device can start an
+	# app. Wait a little longer before trying to use the device.
+	sleep 30
+fi
 
 unset GOBIN
 export GOROOT=$(dirname $(pwd))
@@ -51,7 +53,7 @@ export CGO_ENABLED=1
 export CC_FOR_TARGET=$GOROOT/misc/ios/clangwrap.sh
 
 # Run the build for the host bootstrap, so we can build go_darwin_arm_exec.
-# Also lets us fail early before the (slow) adb push if the build is broken.
+# Also lets us fail early before the (slow) ios-deploy if the build is broken.
 ./make.bash
 
 GOOS=$GOHOSTOS GOARCH=$GOHOSTARCH go build \