Bug 1620950 - Port Bug 1602561. Make PrintUtils.printWindow() act on a BrowsingContext. r=Paenglab

Port of https://hg.mozilla.org/mozilla-central/rev/c78f989b17befffd3009ce9fea4103a759bbbd71

mail/base/content/specialTabs.js

@@ -597,7 +597,7 @@ var contentTabBaseType = {
         break;
       case "cmd_print":
         let browser = this.getBrowser(aTab);
-        PrintUtils.printWindow(browser.outerWindowID, browser);
+        PrintUtils.printWindow(browser.browsingContext);
         break;
       // XXX print preview not currently supported - bug 497994 to implement.
       // case "cmd_printpreview":
@@ -1583,7 +1583,7 @@ var specialTabs = {
           break;
         case "cmd_print":
           let browser = this.getBrowser(aTab);
-          PrintUtils.printWindow(browser.outerWindowID, browser);
+          PrintUtils.printWindow(browser.browsingContext);
           break;
         // XXX print preview not currently supported - bug 497994 to implement.
         // case "cmd_printpreview":

mail/components/compose/content/ComposerCommands.js

@@ -2078,10 +2078,8 @@ var nsPrintCommand = {
   doCommandParams(aCommand, aParams, aRefCon) {},
 
   doCommand(aCommand) {
-    try {
-      let browser = GetCurrentEditorElement();
-      PrintUtils.printWindow(browser.outerWindowID, browser);
-    } catch (e) {}
+    let browser = GetCurrentEditorElement();
+    PrintUtils.printWindow(browser.browsingContext);
   },
 };
 
@@ -2095,9 +2093,7 @@ var nsPrintPreviewCommand = {
   doCommandParams(aCommand, aParams, aRefCon) {},
 
   doCommand(aCommand) {
-    try {
-      PrintUtils.printPreview(PrintPreviewListener);
-    } catch (e) {}
+    PrintUtils.printPreview(PrintPreviewListener);
   },
 };
 

mail/components/compose/content/MsgComposeCommands.js

@@ -2409,20 +2409,12 @@ function DoCommandClose() {
 }
 
 function DoCommandPrint() {
-  try {
-    let editor = GetCurrentEditorElement();
-    PrintUtils.printWindow(editor.outerWindowID, editor);
-  } catch (ex) {
-    dump("#PRINT ERROR: " + ex + "\n");
-  }
+  let browser = GetCurrentEditorElement();
+  PrintUtils.printWindow(browser.browsingContext);
 }
 
 function DoCommandPrintPreview() {
-  try {
-    PrintUtils.printPreview(PrintPreviewListener);
-  } catch (ex) {
-    Cu.reportError(ex);
-  }
+  PrintUtils.printPreview(PrintPreviewListener);
 }
 
 /**