Bug 1561502, r=Honza

Differential Revision: https://phabricator.services.mozilla.com/D42122

--HG--
extra : moz-landing-system : lando

devtools/client/jsonview/converter-child.js

@@ -363,7 +363,10 @@ function onContentMessage(e) {
   const value = e.detail.value;
   switch (e.detail.type) {
     case "save":
-      Services.cpmm.sendAsyncMessage("devtools:jsonview:save", value);
+      win.docShell.messageManager.sendAsyncMessage(
+        "devtools:jsonview:save",
+        value
+      );
   }
 }
 

devtools/startup/DevToolsStartup.jsm

@@ -1156,7 +1156,7 @@ const JsonView = {
     // Register for messages coming from the child process.
     // This is never removed as there is no particular need to unregister
     // it during shutdown.
-    Services.ppmm.addMessageListener("devtools:jsonview:save", this.onSave);
+    Services.mm.addMessageListener("devtools:jsonview:save", this.onSave);
   },
 
   // Message handlers for events from child processes
@@ -1166,8 +1166,8 @@ const JsonView = {
    * in the parent process.
    */
   onSave: function(message) {
-    const chrome = Services.wm.getMostRecentWindow("navigator:browser");
-    const browser = chrome.gBrowser.selectedBrowser;
+    const browser = message.target;
+    const chrome = browser.ownerGlobal;
     if (message.data === null) {
       // Save original contents
       chrome.saveBrowser(browser);