fix display of fiddles that DON'T have compile errors

BUG=skia:

Review URL: https://codereview.chromium.org/644253003
diff --git a/experimental/webtry/res/js/webtry.js b/experimental/webtry/res/js/webtry.js
index 8bce06b..18190e9 100644
--- a/experimental/webtry/res/js/webtry.js
+++ b/experimental/webtry/res/js/webtry.js
@@ -269,7 +269,7 @@
         // image to display.
         endWait();
         body = JSON.parse(e.target.response);
-        if (body.compileErrors.length) {
+        if (null != body.compileErrors && body.compileErrors.length) {
           html = "";
           for (i = 0 ; i < body.compileErrors.length ; i++) {
             compileError = body.compileErrors[i];
diff --git a/experimental/webtry/webtry.go b/experimental/webtry/webtry.go
index 34aa47e..2096f7d 100644
--- a/experimental/webtry/webtry.go
+++ b/experimental/webtry/webtry.go
@@ -937,9 +937,8 @@
 		}
 
 		m := response{
-			Message: message,
-			Img:     base64.StdEncoding.EncodeToString([]byte(png)),
-			Hash:    hash,
+			Img:  base64.StdEncoding.EncodeToString([]byte(png)),
+			Hash: hash,
 		}
 		resp, err := json.Marshal(m)
 		if err != nil {