Parse XML from text, in content side.

The already-parsed responseXML property cannot be message passed from background->content.  So take the responseText form and re-parse it, on the content side.

Fixes #2980

src/bg/api-provider-source.js

@@ -231,6 +231,16 @@ function GM_xmlHttpRequest(d) {
 
   let port = chrome.runtime.connect({name: 'UserScriptXhr'});
   port.onMessage.addListener(function(msg) {
+    if (msg.responseState.responseXML) {
+      try {
+        msg.responseState.responseXML = (new DOMParser()).parseFromString(
+            msg.responseState.responseText,
+            'application/xml');
+      } catch (e) {
+        console.warn('GM_xhr could not parse XML:', e);
+        msg.responseState.responseXML = null;
+      }
+    }
     let o = msg.src == 'up' ? d.upload : d;
     let cb = o['on' + msg.type];
     if (cb) cb(msg.responseState);

src/bg/on-user-script-xhr.js

@@ -55,18 +55,19 @@ function open(xhr, d, port, tabUrl) {
     }
 
     try {
-      responseState.responseXML = xhr.responseXML;
+      // Pass a flag to the content side, that the XML should be parsed.
+      responseState.responseXML = !!xhr.responseXML;
     } catch (e) {
       // Ignore failure.  At least in responseType blob case, this access fails.
     }
 
     switch (event.type) {
-      case "progress":
+      case 'progress':
         responseState.lengthComputable = event.lengthComputable;
         responseState.loaded = event.loaded;
         responseState.total = event.total;
         break;
-      case "error":
+      case 'error':
         console.log('error event?', event);
         break;
       default:
@@ -78,7 +79,7 @@ function open(xhr, d, port, tabUrl) {
     }
 
     port.postMessage(
-        {src: src, type: event.type, responseState: responseState});
+        {'src': src, 'type': event.type, 'responseState': responseState});
   }
 
   [

src/user-script-obj.js

@@ -10,7 +10,7 @@ reference any other objects from this file.
 // Increment this number when updating `calculateEvalContent()`.  If it
 // is higher than it was when eval content was last calculated, it will
 // be re-calculated.
-const EVAL_CONTENT_VERSION = 12;
+const EVAL_CONTENT_VERSION = 13;
 
 
 // Private implementation.